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AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage1of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPErrorCodes&SMTPStatusCodes&SMTPReplyCodesReference2010TherecomesatimeinthelifeofaComputerConsultantwhere,oneday,he/shewillhavetodealwithemailserverproblems.
Itisinevitable.
SometimestheseproblemswillbewiththeinterfacingofthemailserverwiththeISP,inparticularaninabilitytosendmail.
Aftercheckingtheusualsuspectssuchaslackofconnection(yourbroadbandlineisdead),faultyrouter,firewallproblems,DNSproblems,oranincorrectSMTPservername(thankstosomecleverISPchangingitsSMTPservernamewithoutinforminganyone–ithappens!
!
),youwilllikelystartdelvingalittledeeperbycheckingifyouremailserverreportsanyerrors.
Dependingontheactualproblemitisencountering,yourmailservermaynotbeabletoprovidedetailedhelponhowtoresolvetheproblem,andmayinsteadonlybeabletoprovideyouwithanSMTPStatusCodeinyourserver'slog(thesecodesarealsoknownasSMTPErrorCodesorSMTPReplyCodes),oremailswillbereturnedtothesenderwitherrortext.
Aclassicreplymightbe,forexample,"SMTPerrorfromremotemailserverafterendofdata-:550Error:Messagecontentrejected",or"SMTPerrorfromremotemailserverafterRCPTTO,5505.
1.
1Userunknown"or"SMTPError:Datanotaccepted"or"SMTPError:Thefollowingrecipientsfailed".
Itisjustforsuchcasesthatwehaveproducedthisdocument(weuseittoo!
!
).
Whatdoes550meanWhatdoes5505.
1.
1mean(or,shortened,whatdoes511mean)Whatdoes"Datanotaccepted"meanSo,usethisdocumentasaquickreferencetocommonSMTPstatuscodesorSMTPerrorcodesforSMTPmailserverssuchasAAMailServer,Alt-NMDaemon,ArGoSoftMailServer,AxigenMailServer,BarracudaSpamFirewall,CMail,CMailServer,E-MailAnywhere,FTGate,GMSMail,InternetAnywhere,KerioMailServer(KMS),LotusNotes,MailEnable,Mailman,MailMax,Mailtraq,MerakMailServer,MicrosoftExchange(ExchangeServer2003NDR,Non-DeliveryReport,errorcodes),NovellGroupWise,Qmail,PostCastServer,PostConf,PostFix,PowerMTA,QKSMTPServer,RockliffeMailSite,SendMail,SquirrelMail,SurgeMail,TFSSecureMessageServer,VisNeticMailServer,WinMail,Zimbra,oranyotherSMTP/ESMTPstandardscompliante-mailMTA.
Note:thefollowinglistofSMTPreplycodescanalsobeusedtotroubleshootEudoraorFoxMailemailproblems,Outlookerrorcodes,OutlookExpresserrorcodes(Windows2000/XP),WindowsMailErrorCodes(Vista),Thunderbirdproblems,orotheremailprogramproblemswhenthoseprogramssendandcollectemailsdirectlytoandfromtheInternetasopposedtothroughacorporateemailsystem.
Theerrorcodesreturnedarethesame.
Finally,therearenobettertoolsforresolvingcomplexSMTPerrorsituationsthantheWHOIS,NameServerLookup,TraceRoute,andPINGtoolsofourownTheUltimateTroubleshooteravailableonourAnswersThatWork.
comwebsite–thatishowweourselvesquicklysolvecomplexSMTPerrorsituations.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage2of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean101–Cannotopenconnection(alsocalledSMTPError1.
0.
1)SMTPError101:TypicallyyourSMTPserveroremailprogramisunabletoevenstartanSMTPsession.
Typicalreplieswillbe"SMTPError101,Erroropeningconnection"or"SMTPError101,cannotopenSMTPstream".
AllSMTPError101errorsusuallypointtoaconfigurationproblem,suchasanincorrectlyspeltSMTPserver,oranIPaddressthatdoesnotexist,oranSMTPportthatdoesnotexistorwhichtherecipientwillnotacceptSMTPconnectionson,orsomeotherprocessisalreadyusingthedefaultSMTPport,port25.
111–Connectionrefused(alsocalledSMTPError1.
1.
1)SMTPError111:TypicallyfromLinuxbasedemailsystemssuchasSquirrelMailandMailman.
Themessagewillusuallygolikethis:"Connectionrefused,111Can'topenSMTPstream".
AllSMTPError111errorsusuallypointtoaninabilityofyourservertocommunicatewiththeremoteSMTPserver(eithertherecipient'sSMTPserveroryourISP'sSMTPserver)ortoaLinux/SMTPsoftwareconfigurationproblem,typically/etc/hostsnotbeingworldreadable,oranewlyinstalledorreconfiguredfirewallpreventingconnectiontotheremoteSMTPserver,orincorrecthostnamesand/ordomains(e.
g.
doesyoursendinghostnamematchyourIPaddressinareverselookup),oreximnotrunning.
Telnetandlogsshouldhelpyouhomeinontheproblem.
211–SystemStatusmessageorSystemHelpReply(alsocalledSMTPError2.
1.
1)SMTPError211:SMTPstatus211prefacesamessageabouttheMailServerstatusoraSystemHelpreplytotheuserrequestinghelpinformation.
YoumightforexampleissueacommandtothemailservertodisplayalistofcommandsyoucanuseandtheserverreplieswithanSMTPReply211followedbythelistyourequested.
214–HelpReplymessage(alsocalledSMTPError2.
1.
4)SMTPError214:SMTPstatus214isusuallyinreplytothe"HELP"command.
Itdisplaysinformationabouttheserver,usuallyaURLtotheFAQpageoftheSMTPsoftwarerunningontheserver.
Asaresultthis"error"isnormallycalledareply,asinSMTPReply214.
220–serviceisrunning(alsocalledSMTPError2.
2.
0)SMTPStatus220:Thisisnormallythefirstmessageyouwillgetbackfromtheserver.
Itmeansthemailserviceisrunning(ie.
yourmailserverisrunning).
Itwillnormallycontainawelcomemessageand/orthetitleoftheSMTPsoftwareand,sometimes,theversionnumberofthemailserversoftware.
SMTPReply220iseffectivelya"HiThere,Ihavejustthissecondfinishedstartingup–Iamreadytogoandatyourcommand"informationalmessage.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage3of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean221–Thedomainserviceisclosingthetransmissionchannel(alsocalledSMTPError2.
2.
1)SMTPError221:Theserverisendingthemailsession–itisclosingtheconversationwiththeISPasithasnomoremailtosendinthissendingsession.
SMTPStatus221isoftenmisconstruedasanerrorcondition,whenitisinfactnothingofthesort.
Themailserverissimplytellingyouthatithasprocessedeverythingitwasgiveninthisparticularsession,anditisnowgoingbackintowaitingmode.
BecauseSMTPstatus221isoftenmisinterpreted,withsomemailserverstheNetworkAdministratorshavechangedthedefaulttextofSMTPReply221tosomethingmoremeaningfulandlessalarming.
Forexample,atypicalSMTPreply221mightsay"221Goodbye"or"221Closingconnection",orthemostirritatingonewe'veseen"221Bye",Arrrgghh–canyoublameanyoneforthinkingtheremightbeaproblemOfcoursenot!
SosomeNetworkAdministratorsarethesedaysbeingquiteimaginativebychangingthedefaulttextofSMTPreply221tomoreuserfriendlymessageslike:"221Thankyouforyourbusiness"(Ilovethatone!
),or"221Allmessagesprocessedsuccessfullyinthissession,SMTPconnectionisclosing".
250–RequestedmailactionOKcompleted(alsocalledSMTPError2.
5.
0)SMTPStatus250:Themailserverhassuccessfullydeliveredthemessage!
ThisisthebestSMTPreply(250)toreceive-yourmessagehasbeenacceptedandtransmittedOK!
Yippee.
250iseffectivelyastatuscoderatherthananerrorcode–thereisnosuchthingasanSMTPerror250.
251–Usernotlocalwillforward(alsocalledSMTPError2.
5.
1)SMTPStatus251:TheemailaccountisnotlocaltotheISPserverbuttheISPserverwillaccepttheemailandwillforwardit(theserverwillRELAYyourmessage,thisisthemostcommonactionforISPMailservers–therecipientwillseeyourISPinthemailheaderasoneofthefirsthopsonthewaytotherecipient'semailsystem).
SMTPError251isthereforemoreofaninformationalmessagefortechnicianstrackinghowamessagereacheditsdestination.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage4of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean252–CannotVRFY(verify)theuser–theserverwillacceptthemessageandattempttodeliverit(alsocalledSMTPError2.
5.
2)SMTPStatus252:Theuseraccountappearstobevalidbutcouldnotbeverified,howevertheserverwilltrydodeliverthemessage.
TherearesometimescircumstanceswhereanemailaddressappearstobevalidbutcannotbeverifiedasdefinitelyvalidduringtheSMTPsessionbetweenthesendingserver(yourserver)andthenextservertoacceptyourmessage.
Thiscanhappenforexampleinverylargecorporationwherethefirstemailreceivingservermightonlybeanemailexchangerserver,agatewayservertotheeventualserverwhichholdstheusermailboxesandwhichcanverifyiftheintendedrecipientexistsinthatorganization.
WhenthishappensthegatewayserverwillreplywithanSMTPError252tellingyoursendingserverthatitcannotverifytheuserpartoftheemailaddress,thatthedomainpartisOK,andthatitwillforwardyouremailtoaserverwhichcandothecheckingandeventuallydelivertotheusermailboxifitexists.
354–Startmailinputendwith.
,or,asalesscrypticdescription–"FROMandTOinformationreceived,nowpleaseprovidemessagebodyandmarkitsendwith.
"(alsocalledSMTPError3.
5.
4)SMTPError354:ThisisnormallyinresponsetotheDATAcommand.
TheserverhasreceivedtheFromandToinformationandisnowaskingforthe"MessageBody",themainpartofthemessagewhichshouldbeendedbytwoblanklinesseparatedbyadot(period).
Therefore,onreceivinganSMTPReply354thesendingservershouldsendthebodyofthemessagetothereceivingserverandindicatetheendofthemessagebodywith.
(notethefullstopbetweenthetwoCarriage_Return-Line_Feed's).
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage5of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean420–Timeoutcommunicationproblemencounteredduringtransmission.
ThisisaNovellGroupWiseSMTPerror(alsocalledSMTPError4.
2.
0)SMTPError420:InourexperienceonlyNovellGroupWiseserversusethiserror(weuseGroupWise!
).
YouwillgetaGroupWiseGWIA(GroupWiseInternetAgent)420TCPWriteErroror420TCPReadErroriftherearecommunicationproblemsduringtransmissionoftheactualmessageafterthesendingandreceivingservershaveactuallyconnected.
Asmallnumberof420SMTPerrorsisnormalasoccasionalpeaksofInternetusagemaydelaythetransmissionofanemailwithattachmentsomuchthatatimeoutoccurs.
WhenatimeoutoccursonaGWIAsend,themessageisqueuedupinthe\WPGATE\DEFERdirectoryforprocessingatalatertime(asdefinedinConsoleOneorGWIA.
CFG).
Ifyouexperience420errorsonlywithspecificrecipientthenitisquitelikelythattherecipient'santispamfirewalldoesnotlikeyourserver,yourserver'sexternalIPaddress,orthatyourserver'sHELOcommandusesanoutboundidentificationthatdoesnotmatchyourserver'sexternalIPaddress(checkthatyoursendingdomain'sDNSissetupcorrectly).
InanidealworldawellbehavedrecipientservershouldreallybeissuingyourGroupWiseserverwitha554errorratherthantimingoutandcausingtheGroupWiseGWIAtofaultwitha420error.
Ifyouexperiencetoomany420errorswithallemailcommunications,thenyouhaveaphysicalcommunicationproblemsomewhere.
Thiscouldbeyourserver'snetworkcard,thenetworkpointthatyourserverispluggedinto,yourswitch(es),yourrouter(s),yourfirewall,oryourInternetline–problemscausedbyrouterswithdifferentMTUsizesisaclassicissue.
Unlessthelogsofallthosevariousproblempointscangiveyouaninstantanswer,theonlywayyouwillgettothebottomoftheproblemistouseapackettracingandinspectionprogramlikeEtherealorWireshark,itssuccessor,ifyou'rerunningGroupWiseonaWindowsorLinuxserver;onNetWareyouronlychoiceisPacketScanwhichyoucangetherehttp://support.
novell.
com/docs/Readmes/InfoDocument/2967287.
html.
Inthefinalanalysis,ifthetracingofpackets,andthechangingofhardwaredoesnothelpthendonotdiscountaslightlyfaultyharddiskbeingthecauseofallyourproblems(evenifyourRAIDcontrolleroryourharddisktestingsoftwaredoesnotdetectanyproblem!
).
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage6of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean421–Servicenotavailable–thesendingemailprogramshouldtryagainlater(alsocalledSMTPError4.
2.
1)SMTPError421:TheMailtransferserviceisunavailablebecauseofatransientevent.
SMTPreply421canbecausedbymanythingsbutgenerallyindicatesthatthemailserverwhichreturnsthisstatuscodeiscurrentlyunavailablebutmaybeavailablelater.
Forexample,theserveradministratormayhavestoppedthemailservicetotroubleshootaproblem,orthemailserverisrightinthemiddleofrebooting,orthemailserveriscurrentlyprocessingtoomanyincomingmessagesorincomingrequests,etc.
.
.
.
Note:"MailServer"inthiscasecanbeanyofthemailserversonthemessage'sroute–thesendingserver(yourserver),theISPSMTPserver,ortherecipient'smailserver.
Clearly,ifyourepeatedlyreceiveanSMTPstatus421thentheproblemisnolongerofatransientnatureandyouneedtoinvestigateorinformtherelevantnetworkadministrator,ISPtechsupport,ortherecipient.
422–Therecipient'smailboxisoveritsstoragelimit(alsocalledSMTPError4.
2.
2)SMTPError422:Eithertherecipient'smailboxisoveritsstoragelimitorthemessagedeliverydirectory(folder)ontherecipient'smailserveriscurrentlyoverasizelimitimposedbytheNetworkAdministrator(e.
g.
possiblyasaresultofthemailserverhavingbeendownforsometime,havingbeenrepaired,andcurrentlyintheprocessofcollectingthousandsofqueuedupmessages).
431–Therecipient'smailserverisexperiencingaDiskFullcondition(alsocalledSMTPError4.
3.
1)SMTPError431:Therecipient'smailserverisexperiencingaDiskFullerrorcondition,oranOutofMemory(toomanyfilehandles)errorcondition(MicrosoftExchange).
432–Therecipient'sExchangeServerincomingmailqueuehasbeenstopped(alsocalledSMTPError4.
3.
2)SMTPError432:ThisisanSMTPstatusresponsespecifictoMicrosoftExchangeServer.
Itindicatesthattherecipient'smailqueueontheirExchangeServerhasbeenstopped(frozen),probablywhiletheNetworkAdministratortroubleshootssomeproblem.
441–Therecipient'sserverisnotresponding(alsocalledSMTPError4.
4.
1)SMTPError441:Thisisanerroremanatingfromyourserverindicatingthattherecipient'sserverisnotresponding.
Yourserverwillautomaticallytryagainanumberoftimes–howmanydependsonhowyourserverhasbeenconfigured.
442–Theconnectionwasdroppedduringtransmission.
(alsocalledSMTPError4.
4.
2)SMTPError442:Yourserverstarteddeliveringthemessagebuttheconnectionwasbrokenduringtransmission.
Thismaybeanunusualtransienterror–however,ifitkeepshappeningyoushouldinvestigatepossibleproblemswithyourserver'snetworkcard,yourInternetrouters,processeshoggingtheresourcesofyourserver,andanythingelsewhichcouldresultinanetworkconnectionbeingbroken.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage7of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean446–Themaximumhopcountwasexceededforthemessage(alsocalledSMTPError4.
4.
6)SMTPError446:Themaximumhopcountwasexceededforyourmessage.
Themostlikelycauseofthiserrorstatuscodeisthatyourmessageisloopinginternallyonyourserver,internallybetweentwoofyourorganisation'sservers,or,sometimes,loopingbetweenyourserverandtherecipient'sserver.
447–Youroutgoingmessagetimedout.
(alsocalledSMTPError4.
4.
7)SMTPError447:Youroutgoingmessagetimedoutbecauseofproblemswiththereceivingserverwhoobjectedtoyourmessage.
Typicallythereisaproblemwiththemessageheader(suchastoomanyrecipients,inmostcases,oraprotocoltimeoutbetweenthetwoservers).
449–Routingerror(alsocalledSMTPError4.
4.
9)SMTPError449:ThisisaMicrosoftExchangeServerspecificerrorcode.
AsperMicrosoft'sdocumentationthiserrorcodeisreturnedwheneitherofthefollowingconditionsoccurs:anSMTPconnectorisconfiguredtouseDNSwithoutasmarthostandalsousesanon-SMTPaddressspace(e.
g.
X.
400),orAmessagewassenttoarecipientwhowasidentifiedasamemberofaroutinggroupthatwasdeleted.
MicrosoftrecommendsusingtheWinRoutetooltotroubleshootthiserror(MicrosoftKnowledgebasearticle281382)450–Requestedactionnottaken–Themailboxwasunavailableattheremoteend.
AsecondarySMTPerrorcodemayfollow"450"torefinethereasonforthefailuretotransmitthemessage,e.
g.
"SMTPError450(alsocalledSMTPError4.
5.
0)SMTPError450:Theservercouldnotaccessthemailboxtodeliverthemessage.
Thiscouldbecausedbyaprocessontheremoteservertidyingupthemailbox,ortheremotemailboxcouldbecorrupt,ortheremotemailboxmaybestoredonanotherserverwhichiscurrentlyoffline,orthenetworkconnectionwentdownwhilesending,ortheremotemailserverdoesnotwanttoacceptmailfromyourserverforsomereason(IPaddress,blacklisting,etc.
.
).
IngeneralSMTPError450isatransienterrorattheremoteend(thedestination),oratoneoftheroutersorserversenroutetotheremoteend,andshouldinduceyourmailservertoretryafterit'spresetretryinterval.
ExampleofanSMTPError450replymessage:"450Pleasetryagainlater",oraclassicNovellGroupWise450statusmessage:"Themessagethatyousenthasbeendelayed.
Thereasongivenforthedelay:450Hostdown(relay.
clara.
net)".
SMTPError450isoftenfollowedbyasecondSMTPerrorcodetorefinethereasonfortheemailnotreachingitsdestination.
Forexample:"SMTPError4505.
2.
3MsgSizegreaterthanallowedbyRemoteHost".
WhenthatisthecaseandIftheerrormessageisnotasclearlywordedasinthisexample,thensimplysearchthisdocumentforthesecondaryerrorcode.
InthiscasesearchingthisdocumentforSMTPError523orSMTPError5.
2.
3wouldyieldanexplanationidenticaltothewordingabove.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage8of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean451–Requestedactionaborted–Localerrorinprocessing.
orhasrecentlysentspam(alsocalledSMTPError4.
5.
1)SMTPError451:TheactionhasbeenabortedbytheISP'sserver.
"Local"referstotheISP'sserver.
ThiserrorisusuallyduetooverloadingattheISPfromtoomanymessagesortransientfailures.
Typicallysome[hopefully]temporaryeventpreventsthesuccessfulsendingofthemessage.
Thenextattempttosendbyyourservermayprovesuccessful.
Ifthiserrorkeepsoccurringtothepointthatithaseffectivelylostitstransientnatureandhasbecome.
.
.
.
.
frequent(!
!
),thentheproblemisatyourendandyoushouldcheckyourownmailserver(ifyouemailoutofacorporatenetwork),communicationsonyourside(router,servernetworkcard),orinformyourISPifyourmailserverrelaysthroughyourISPorifyouareahomeuseremailingoutthroughOutlook,OutlookExpress,WindowsMail,orsimilaremailprogram.
ExampleoftypicalSMTPError451returnmessages:"SMTPerror451Unabletocompletecommand,DNSnotavailableortimedout"or"451Domainofsenderaddressdoesnotresolve"or"451ErrorgettingLDAPresultsinmap",or"4514.
7.
1Greylistinginaction,pleasecomebackin00:02:00[minutes]".
WiththeoriginalSMTPstandardshavingbeeninventedbeforespambecausethescourgeoftheInternet,therearenoSMTPerrorcodesdedicatedtoanti-spamerrors.
Asaresult,SMTPError451isnowincreasinglyalsousedtoindicatethatamessagehasbeenrejectedbytheremoteserverbecauseofanti-spammeasures.
Atypicalerrormightbe,forexample:"SMTPerrorfromremotemailserverafterendofdata,host:451hasrecentlysentspam.
Ifyouarenotaspammer,pleasetrylater.
".
Ifallanti-spamrelatedSMTP451errorsareasdescriptiveastheoneabove,thentheerroritselfwilltellyouwhatyouneedtodo.
Asageneralrule,however,youwillmosttimesneedtotakesomemeasurestohaveeitheryourserver,oryourISP'sserver,takenoffsomeInternetblacklistusedbytherecipient.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage9of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean452–Requestedactionnottaken–Insufficientstorage.
(alsocalledSMTPError4.
5.
2)SMTPError452:TheISPserver'sdisksystemhasrunoutofstoragespace,sotheactionhadtobecancelled.
UnlessyouarewithanISPwhichissoslackthattheyhavenotimplementedDiskFullAlerts,thiserrorusuallyindicatesthatyourISP'smailserverisoverloadedfromtoomanymessages.
ThiscanhappeneventothebestISPswhen,forexample,therehavebeenproblemsandnoneoftheISP'scustomerscouldsendmail;assoonastheproblemsarefixedthereisalmostalwaysasituationwherethousandsofusersandorganizationsaretryingtosendmailallatthesametime,andthosenumberscanoccasionallyresultintheISP'smailservers'harddiskstemporarilyfillingup,withSMTPError452beingtheresult.
Thenextattempttosendbyyourservermayprovesuccessful.
SMTPError452:MostISPsmailserversimposeamaximumnumberofconcurrentconnectionsthatclient'smailserverscanattempttomake,andtheyusuallyalsohavealimitonthenumberofmessagesthataresentperconnection.
Withbusinesscustomersthesemaximumsarerarelyreached,ifever.
Nevertheless,Ifyouhavealotofmessagesqueuedup,forexampleasaresultoftheconnectiontoyourISPgoingdownforasignificantamountoftime(andyouhavehundredsofusersinyourorganization,orithappenedjustasyouwereabouttosendthatlargemailshot!
),therecouldbeasituationwheretheoutputofmessagesfromyourservergoesoverthemaximumnumberofmessagesperconnectionallowedbyyourISP.
ThisisanothercasewheretheISP'sservermayissuea452SMTPerror.
Asabove,thenextattempttosendbyyourservermayprovesuccessful.
SMTPError452:Thiserrorcanalsobeindicativeofaproblemonyourownmailserver.
HereisanexampleofanSMTP452error:""452Outofmemory"465–CodePageunavailableontherecipientserver(alsocalledSMTPError4.
6.
5)SMTPError465:ThisisanExchangeServer-specificerrorcode.
Thiserrorisreturnedbytherecipient'sserveriftheincomingemailspecifiesaCodePagethatisnotinstalledontherecipient'sserver,normallybecausenotalllanguagefileswereinstalledontheserverduringeithertheinstallationofWindowsorofExchangeServer.
Update:in2010weareseeingothermailserverprogramsandwebapplicationsnowusingSMTPError465.
ForexampletheosTicketproductwillreturn"465SMTP:Invalidresponsecodereceivedfromserver"iftheSMTPserveryouareusinginyourconfigurationofosTicket,requiresauthenticationandyouhavesetuptheauthenticationincorrectly.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage10of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean471–Thisisalocalerrorwiththesendingserverandisoftenfollowedwith"Pleasetryagainlater"(alsocalledSMTPError4.
7.
1)SMTPError471:Thisisalwaysalocalerrorwithyourownmailserver.
SMTPError471(or4.
7.
1)isusuallytaggedontoaprimarySMTPerrorcode,forexample"SMTPError4504.
7.
1",or"SMTPError4514.
7.
1",or"SMTPError5504.
7.
1";example:"4514.
7.
1Greylistinginaction,pleasecomebackin00:02:00[minutes]".
InallthecasesthatwehaveseenSMTPError471isusuallycausedbyanti-spamorvirusscanningsoftwareonyourserver(thesendingserver)gettingintoproblemsthroughabuginthesoftware,orbecauseofabadautomaticupdatefromtheantivirus/anti-spammanufacturer,becauseoflackofmemoryonyourserver,orbecauseofharddiskproblems.
500–Syntaxerrorcommandnotrecognized.
(alsocalledSMTPError5.
0.
0)SMTPError500:ThelastcommandsentbyyourserverwasnotrecognizedasavalidSMTPorESMTPcommand,orisnotformattedinthewaytheserverexpected.
Thisincludessituationswherethecommandistoolong.
Notethatcommandsthatarerecognized,butnotimplemented,arehandledbydifferentstatusmessages(see502and504).
Note:A"500unrecognizedcommand"serverresponseisoftenacaseofantivirussoftwareinterferingwithincomingand/oroutgoingSMTPcommunications.
Readyourantivirus/firewallsoftwaredocumentationthoroughlytosolvetheproblem.
501–Syntaxerrorinparametersorarguments(e.
g.
invalidemailaddress)Cansometimesalsobeindicativeofcommunicationproblems(alsocalledSMTPError5.
0.
1)SMTPError501:Thecommandwascorrectandrecognised,buttheparameters(thearguments,e.
g.
emailaddress)werenotvalid.
Forexample,thefollowingemailaddresswilldefinitelygiveanSMTPError501withmostmailservers,happy\_larry@hotmail.
com,as"\"isnotallowedinemailaddresses,whichmakesthisemailaddressinvalid.
InthevastmajorityofcasesSMTPError501iscausedbyinvalidemailaddresses.
Forexample,atypicalreturnerrormessagemightbe:"doesnotlikerecipient.
Remotehostsaid:501InvalidAddress".
Incaseswheretheerrorisnotcausedbyaninvalidemailaddress,anSMTPError501,particularlyifrepeated,canbeindicativeofcommunicationsproblems,suchasanoisyline,intermittentdropsinnetworkconnections,etc.
.
.
502–Commandnotimplemented.
(alsocalledSMTPError5.
0.
2)SMTPError502:Thecommandorfunctionissuedbyyourmailserverisvalidbuthasnotbeenactivated(typically,itisnotsupportedonthisparticularserver).
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage11of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean503–Badsequenceofcommands.
orThismailserverrequiresauthentication(alsocalledSMTPError5.
0.
3)SMTPError503:IntheoriginalstandardsSMTPStatus503indicatesthatthecommandshavebeensentinthewrongorder,forexampleyourmailserverhassentthe"Hello"commandbeforesendingthe"Mail"command.
Thiscanoftenbecausedbyadropinnetworkconnectionjustasyourserverwassendingacommand,resultingintheISP'sservernotreceivingitandconsequentlynotunderstandingthecommandthatfollowedit.
Note:thiserror,particularlyifrepeated,canbeindicativeofcommunicationsproblems,suchasanoisyline,intermittentdropsinnetworkconnections,etc.
.
.
SMTPReplyCode503isnowadaysmoreoftenanindicatorthattheSMTPserveryouaretryingtouserequiresauthenticationandyoutriedtosendamessagewithoutauthentication(username+password).
ThisSMTPError503ispermanentinthattheSMTPserverwillnotloganyerrorsinitsloganditwillnotretry–youwillhavetoresendtheemailusingauthentication.
Exampleofsuchanerror:"SMTPError(state13):503Thismailserverrequiresauthenticationwhenattemptingtosendtoanon-locale-mailaddress.
Pleasecheckyourmailclientsettingsorcontactyouradministratortoverifythatthedomainoraddressisdefinedforthisserver.
".
504–Commandparameternotimplemented.
(alsocalledSMTPError5.
0.
4)SMTPError504:Thecommandandparameterarebothvalid,buttheparameterisnotimplementedontheISPserver,oranadditionalparameteroractionismissing.
Forexample,anoftenencounteredSMTPError504is:"504Needtoauthenticatefirst".
IfyouarereceivingthiserrorinaMicrosoftExchangeServerenvironmentwheretheerrorshowsupintheApplicationLogasEventID7004or7010,thenreadthisMicrosoftKnowledgebasearticlehttp://support.
microsoft.
com/kb/843106.
510–BadEmailAddress(alsocalledSMTPError5.
1.
0)SMTPError510:Bademailaddress.
Thisstatuscodeisgeneratedbythesender'slocalmailserver.
Iftheemailwasaddressedinternally,thenitmeansthattheaddressee,aswrittenintheemail'sTO,CC,orBCCfields,doesnotexistinyourorganization'semailsystem.
Iftheemailwasaddressedexternally,thentherecipient'semailaddresswasmisspelt.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage12of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean511–BadEmailAddress(alsocalledSMTPError5.
1.
1)SMTPError511:Bademailaddress.
Thiserrorissimilartoerror510andaswitherror510,thisstatuscodeisgeneratedbythesender'slocalmailserver.
Iftheemailwasaddressedinternally,thenitmeansthattheaddressee,aswrittenintheemail'sTO,CC,orBCCfields,doesnotexistinyourorganization'semailsystem.
Iftheemailwasaddressedexternally,thentherecipient'semailaddresswasmisspelt.
512–Thehostserverfortherecipient'sdomainnamecannotbefound(DNSerror)(alsocalledSMTPError5.
1.
2)SMTPError512:ThisSMTPreplycodeisreceivedwhenoneoftheserversonthewaytothedestinationisunabletoresolvethedomainnameofarecipientemailaddress.
Saiddifferently:oneoftheserversonthewaytothedestination,includingyourserveroryourISP,hasaDNSproblemor,possiblycorrectly,doesnotlikeoneoftheemailaddressesinthemessage'sTO,CC,andBCCfields.
Thefirstcheckyoushouldperformtoresolvea5.
1.
2replycodeistocheckalltherecipientemailaddressesforincorrectdomainnames(misspeltdomainnames,or,maybe,totallynon-existentdomainnames)–remember,errorcode512isveryspecificallyanerrorwiththedomainnameofoneoftherecipientemailaddresses.
Youcancalltherecipient(s)orusetheWHOIStoolofTheUltimateTroubleshooter.
Ifalltherecipientemailaddressescheckoutasregardsthedomainpartoftheemailaddresses,thenoneoftheserversonthewaytotherecipient(s)hasDNSproblems–usuallythiswillbeoneofthefirst2serversinthechain,yourownmailserver(oryournetwork)oryourISP'smailserver.
ExamplesoftypicalSMTPerror512messages:"5.
1.
2-Baddestinationhost'DNSHardErrorlookingupdomain",or"SMTPError5505.
1.
2Hostunknown–hostcannotbefound",orhowaboutthisfantasticallyinformativeerrormessage"5.
1.
2Themessagecouldnotbedeliveredbecausetherecipient'sdestinationemailsystemisunknownorinvalid.
Pleasechecktheaddressandtryagain,orcontactyoursystemadministratortoverifyconnectivitytotheemailsystemoftherecipient.
".
Insummary:mostSMTPerror512conditionsarecausedbymisspellingsofthedomainnamepartofarecipientemailaddress.
However,withtheproliferationofspam,error512isalsooftenencounteredbyautomatic"out-of-office"repliestojunkmailbecausethedomainnamesusedbyjunkmailareoftenbogusdomainnames.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage13of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean513–Addresstypeisincorrect(mostmailservers)orRelayingdeniedorAuthenticationrequired(asmallpercentageofmailservers)(alsocalledSMTPError5.
1.
3)SMTPError513:Thisstatuscode(fromthesender'smailserver)isusuallysymptomatic,inanExchange+Outlookenvironment,oftheuser'sOutlookContactshavingbeenimportedfromanothersystemorPSTandwheresomeoftheaddressesarenotdefinedcorrectly.
Or,inanyenvironmentitissimplythattheend-usersimplydidentertheemailaddresscompletelywrongly,suchascopyingitfromawebsiteandnotreplacing"at"with"@",e.
g.
:John.
DoeatUCLA.
edu(whichshouldhavebeenJohn.
Doe@UCLA.
edu),orJohn.
Doe@UCLA.
edu"(",quotes,isnotallowedinemailaddressesandisoftenincludedinerrorasaresultofcopyingandpastinganemailfromsomewhere).
Theusershouldcheckalltherecipientaddressesintheemail,includingthosethatwereinsertedfromContacts.
Note:theSMTPreplycode5.
1.
3isoftenasecondaryreplycode.
Somemailservers,forexample,mightreply"SMTPerror5015.
1.
3Invalidaddress",or"SMTPerror5535.
1.
3Useraddressrequired!
",or"SMTPerror5015.
1.
3Badrecipientaddresssyntax",or"SMTPerror513RelayingDenied-Cannotsende-mailstosomeaddresses",orthisexcellentlyinformationalExchangeServer2007error(thewholeerrormessageisingreenbelow):"SMTPerror5505.
1.
3STOREDRV.
Submit;invalidrecipientaddress.
Deliveryhasfailedtotheserecipientsordistributionlists:Theformatoftherecipient'se-mailaddressisn'tvalid.
Avalidaddresslookslikethis:username@microsoft.
com.
MicrosoftExchangewillnottrytoredeliverthismessageforyou.
Pleasecheckthee-mailaddressandtrysendingthemessageagain,orprovidethefollowingdiagnostictexttoyoursystemadministrator.
5.
1.
3:Theformatoftherecipiente-mailaddressisnotvalid.
ValidSMTPe-mailaddressescancontainonlyletters,numbers,hyphens,periods,andonlyone@symbol.
Troubleshooting:VerifythattheSMTPaddressoftherecipientisformattedcorrectlyandresendthemessage.
"SMTPError513isalsousedbyasmallpercentageofmailserverstoindicateacompletelydifferenterror,namelythatyouneedtoauthenticatetothemailserverbeforebeingabletosendyourmessage(SMTPauthentication).
Atypicalerrormessagemightbe:"SMTPerror553Authenticationisrequiredtosendmailasusername@ispdomainname.
com".
Insuchcasesyousimplyneedtoconfigureyourmailserver,oryouremailprogramtosendemailswithSMTPauthentication.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage14of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean523–TheRecipient'smailboxcannotreceivemessagesthisbig(alsocalledSMTPError5.
2.
3)SMTPStatus523:Thiserrorwillbereceivedwhenthetotalsizeofthemessageyouhavesent(ie:message+allofitsattachments)exceedsthesizelimitsontheRecipient'sserver.
Manycompaniesimplementthegoodpracticeofconfiguringtheirserverswithlimitsonthesizeofemailstheycanreceivetopreventtheirsystemsrunningoutofspaceasaresultofaspamattackwherethespamemailscontainlargeattachments,orasaresultofvalidbutnotverytechnicallysavvysenderssendingenormousscans(throughnotknowingthatscanningat1200dpiratherthantheusuallyperfectlyusableandacceptable300dpi,willcreatehumongousattachments).
Checkthesizeoftheemailyousent,and,specifically,thesizeoftheattachmentsyouincluded,andconsidersplittingyouremailintosmalleremails.
Ifthatdoesnotwork,checkwiththeRecipientthemaximumsizeofemailtheycanreceive,andifthatisstillprohibitivethenconsiderFTParrangementsbetweenyouandtherecipient.
SMTPError523isoftenasecondarySMTPerrorcoderatherthanaprimaryerrorcode,asinthefollowingexamples:"SMTPError4505.
2.
3MessageSizegreaterthanallowedbyRemoteHost"or"SMTPError5525.
2.
3Datasizeexceedsmaximumpermitted"or"SMTPError5525.
2.
3Messageexceedsmaximumfixedsize",andsoon.
.
.
.
550–Requestedactionsnottakenasthemailboxisunavailable.
(alsocalledSMTPError5.
5.
0)SMTPError550:Thisresponsecanbecausedbyquiteafewsituations.
SMTPError550willbereturnedbymanyserversIftherecipientemailaddresssimplydoesnotexistontheremoteside(youwilloftenget"550Invalidrecipient"or"550Useraccountisunavailable"or"doesnotlikerecipient-550Addressrejected"or"550Nosuchuserhere"or"550NotourCustomer"or"550Accountnotavailable"or"Remotehostsaid:550–Barack.
Obama@ThisCompany.
com,thisTHISCOMPANY.
COMMailboxDoesNotExist–Givingup").
Inthiscasethesenderoftheemailneedstocontacttherecipientverballytogetthecorrectemailaddress.
SMTPError550willsometimesalsobereturnedbytherecipient'santi-spamfirewallif,forexample,theanti-spamfirewalldoesnotlikethesender(typicallybecausethesenderneedstobewhitelisted).
AtypicalexampleofanSMTPError550returnmessagebyananti-spamfirewallmightbe:240.
240.
240.
240doesnotlikerecipient.
Remotehostsaid:550-VerificationfailedforAnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage15of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeanJohn.
Doe@YourDomain.
com550-Previous(cached)calloutverificationfailure550SenderverifyfailedGivingupon240.
240.
240.
240.
SMTPError550willalsobereturnediftheuser'smailboxisnotlocalandMailRelayisnotenabled,orthesendingaddressisinvalid(thelatterisaway,bytheremoteserver,tocontrolspam).
OthersituationsofSMTPError550includesendingmailtorecipientsoutsideofyourdomainwherethisisnotallowed.
SMTPError550isalsoreturnedwhenyouareattemptingtosendthroughaserverwhichrequiresSMTPauthenticationandyouhavenotsuppliedcredentials(ie.
yourmailserver,oremailprogram,isattemptingtosendwithoutSMTPauthentication)YetanothersetofcircumstanceswhereanSMTPerror550mightbeissuedincludeanincorrectFromaddresswhenusedwithanISPwhereyoucansendmailonlyiftheFromaddressisfromadomainthattheyhostforyou(atthetimeofwriting,September2008,BritishTelecomintheUKissuchanISP–youhavetonotifythemthroughalengthy,ridiculous,andalmostsouldestroyingprocedure,involvingprovingthatyouownthedomain,forthemtoallowyoutosendemailsfromadomainnamethattheydonothostforyou).
AnothercaseofSMTPError550iswhentherecipient'sserverisdown(orcannotreceivemailatthistime)andtheISP'sserverswillretryperiodicallyforalimitedamountoftime(thisisoftenaccompaniedbyareturnmailfromyourISPinformingthesenderoftheemailofjustthatsituation).
AnothercaseofSMTPError550iswhentherecipient'sserverrequiresyoutomakeachangetotheTopartofyouremailtoachievesuccessfuldeliveryoftheemail(someorganizationsconfiguretheirreceivingmailserversinthiswaywhentheyhavechangedtheirdomainnameandwanttoforcethesenderstoupdatehisaddressbooks–forexample,My-Great-Company.
comhaschangeditsAnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage16of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeandomaintoMyGreatCompany.
comandyouarestillusingtheolddomainname).
YetanothersetofcircumstanceswhentheSMTPError550isreceivediswhentherecipient'smailboxhasbeensuspended.
Forinstance,theQMAILSMTPmailprogramhasanendearingwayoftellingyouaboutamailboxthathasbeensuspended:"I'mafraidIwasn'tabletodeliveryourmessagetothefollowingaddresses.
Thisisapermanenterror;I'vegivenup.
Sorryitdidn'tworkout.
:doesnotlikerecipient.
Remotehostsaid:550[SUSPEND]Mailboxcurrentlysuspended-Pleasecontactcorrespondentdirectly.
".
AnothercircumstanceofanSMTPError550iswhentherecipient'smailboxhasbeendisabled.
Thetypicalreasonsforthisarethemailboxbeingfull(theuserneedstodeletemessagesbeforenewoneswillbeaccepted)ortheusernothavingpaidabill.
Anexampleofthereplyyouwillreceiveis:"550mailboxtemporarilydisabled"551–Usernotlocalorinvalidaddress–Relaydenied.
(alsocalledSMTPError5.
5.
1)SMTPError551:Ifneitherthesendingmailaddressnortherecipient'saddressarelocallyhostedbytheserver,thentheISP'sserversmayrefusetorelaythemessageon.
SomeISPsimplementthisrestrictiontothwartspammers.
Inourview,hereatAnswersThatWork,thisisalazyandincompetentmethodoffightingspamasmostofthetimeitdoesnothingbutinconvenienceno-oneotherthantheISP'svastmajorityofconsiderateandlawabidingusers.
Inourexperiencethisusuallygoeshandinhandwithbarelycompetenttechnicalsupport.
Atthetimeofwriting,14-Sep-2008,atypicalculpritforthisisBT,BritishTelecom,intheUK.
Thewayinwhichitmanifestsitselfisasfollows:youhaveadomainthatishostedbyCrystalTech.
combutyourISPisDodgyISP.
comandyoutrytosendemailsfromyourdomaintoWhatANiceBunchOfPeopleYouAre@yahoo.
usa.
NeitheryourdomainnorYahoo.
usaarehostedbyDodgyISP.
com,asaresultyouremailisnotacceptedbyDodgyISP'smailserversandyourmailserverisreturnedanSMTPError551.
TocorrecttheproblemyouhavetocallDodgyISP.
comandaskthemtoenteryourdomainnameasanallowedsender.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage17of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean552–Requestedmailactionsaborted–Exceededstorageallocation.
(alsocalledSMTPError5.
5.
2)SMTPError552:Therecipient'smailboxhasreacheditsmaximumallowedsize(thisisoftenaccompaniedbyareturnmailfromyourISPormailserverinformingthesenderoftheemailofjustthatsituation).
Example:"552sorry,mailboxAlan@ThisCompany.
comisoverquotatemporarily(#5.
1.
1)".
SomemailservershaveextendedthescopeofSMTPReplyCode552byalsoincludingerrorswherethesizeoftheincomingmessageexceedsthesizelimitspecifiedbytheNetworkAdministrator,asin,forexample,"SMTPError5525.
2.
3Messagesizeexceedsfixedmaximummessagesize(7000000)",whicheffectivelysaysthattheincomingmessagewaslargerthanthe7MBlimit(7,000,000bytes)setbytheNetworkAdministratoroftherecipient'smailserver.
553–Requestedactionnottaken–Mailboxnameinvalid.
(alsocalledSMTPError5.
5.
3)SMTPError553:Thereisaninvalidemailaddressinthe"To","CC",or"BCC"fieldoftheemailmessage.
HereisatypicalSMTPError553response:"Hi.
ThisistheQMAIL-sendprogramat.
I'mafraidIwasn'tabletodeliveryourmessagetothefollowingaddresses.
Thisisapermanenterror;I'vegivenup.
Sorryitdidn'tworkout.
:doesnotlikerecipient.
Remotehostsaid:5535.
3.
0.
Addresseeunknown.
Givingup.
".
SMTPStatus553isalsosometimesreturnedbyanISPmailserver.
WhenthishappensthisisalmostalwaysbecauseyouaretryingtosendthroughaspecificISP'sSMTPserverandyetyouarenotconnectedtotheInternetthroughthatISP,e.
g.
youareconnectedtotheInternetthroughaComcastbroadbandconnectionbutyouremailprogram(OutlookExpress,WindowsMail,.
.
.
)isconfiguredtosendemailsthroughtheSMTPserverofTiscali.
Atypicalsucherrormessagemightbe:"553sorry,relayingdeniedfromyourlocation".
554–Transactionfailed.
NowadaysSMTPstatus554isinmostcasesreturnedwhentherecipientserverbelievesyouremailisspamoryourIPaddressorISPserverhasbeenblacklistedononeormoreSMTPError554:Therewasapermanenterrortryingtocompletethemailtransactionwhichwillnotberesolvedbyresendingthemessageinitscurrentform.
Somechangetothemessageand/ordestinationmustbemadeforsuccessfuldelivery.
Forinstance,YahoooftenreturnsthefollowingiftherecipientemailaddressdoesnotexistontheYahoosystems:"554deliveryerror:Thisuserdoesn'thaveaYahoo.
comaccount".
AnothertypicalYahooSMTPError554replyis:"554deliveryerror:SorryyourmessagetoAnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage18of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeanInternetblacklists.
orWithYahoo,ontheotherhand,thisusuallymeanstheemailaddressdoesnotexistorhasbeendisabled.
orWithIBM'sLotusDominothisiseitheraDominobugoraDiskFullerror(alsocalledSMTPError5.
5.
4)cannotbedelivered.
Thisaccounthasbeendisabledordiscontinued".
InthecaseofanIBMLotusDominoserverontheotherhand,thisiseitheradiskfullerror(thefirstthingtocheck),oraLotusDominobugwhichhasappearedinvariousguisesinmanyversionsofLotusDominoasfarbackas2002.
Eightyears,EightyearsandcountingandIBMstillsufferfromthisbug–themindboggles!
ClickonthislinktoreadthelatestIBMKnowledgebasearticleonthiserroratthetimeofwriting:http://tinyurl.
com/ygfqoov.
Inmostothercases,however,arecipientmailserverwillreturnanSMTPREPLY554whenitsanti-spamfirewalldoesnotlikethesender'semailaddress,orthesender'sIPaddress,orthesender'sISPserver(because,forexample,theyarelistedinanRBL)andwhereyouwillthereforeeitherneedtohavethesenderwhitelistyouintheiranti-spamprogram/appliance,or,worse,youwillneedtotakestepstohaveeitheryourIPaddressoryourISP'sservers(ifyousendmailthroughyourISP)de-listedfromoneormoreRBLs(RBL=RealtimeBlackholeList–alsocalledRealtimeBlacklistnowadays).
Forexample,a554errorreturnedbyaComcastservermightlooklikethis:"Username@comcast.
netSMTPerrorfromremotemailserverafterinitialconnection:hostmx2.
comcast.
net:554IMTA11.
emeryville.
ca.
mail.
comcast.
netwasfoundononeormoreDNSBLs,seehttp://help.
comcast.
net/content/faq/BL000010",whereDNSBLs=DNSBlacklists.
Inthiscase,therefore,ifyougetsuchamessagebackitistellingyouyourIPaddress,oryourISP'smailserverislistedononeoftheanti-spamblacklistdatabasesthatComcastusestofilteroutspamonincomingemailstoComcastmailboxes–clickthelinkprovidedintheerrormessagetoseehowyoumaybeabletoun-blacklistyourselfasfarasComcastisconcerned.
HereisanotherexamplefromtheOZEMAILISPinAustralia,"SMTPerrorfromremotemailserverafterinitialconnectiontohostmx1.
ozemail.
com.
au:554filter.
ozemail.
com.
au"–notveryinformative,asyoucansee,butthenameoftheserverreturningtheSMTPreply554iswhatgivesthisawayasOZEMAIL'santi-spamnotlikingyou:filter.
ozemail.
com.
au.
"Filter"inthenameofarecipientserverisalmostalwaysanindicationthatthatserverisananti-spamandantivirusserver.
AndhereisaTwitterexample:"SMTPerror:EmailError:RCPTTOinvalidmailserverresponse:5545.
7.
1:Recipientaddressrejected".
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage19of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeanNotethatSMTPError554canalsooftenbeburiedinthemiddleofSMTPError550errors.
HereisanexampleofarecipientmailserverreturninganSMTPError554becauseitsBarracudaanti-spamfirewallappliancerejectedtheemail(thecause,asshownbelow,isBarracudaReputationwhichmeansyourIPaddressoryourISP'sserverisblacklistedonBarracuda'sRBL):240.
240.
240.
240doesnotlikerecipient.
Remotehostsaid:550-VerificationfailedforJohn.
Doe@YourDomain.
com550-Called:250.
250.
250.
250550-Sent:RCPTTO:John.
Doe@YourDomain.
com550-Response:554:Serviceunavailable;Clienthost[server11.
virgohosting.
net]blockedusingBarracudaReputation;http://recipientdomain.
barracudacentral.
com/q.
cgiip=230.
230.
230.
230550SenderverifyfailedGivingupon240.
240.
240.
240Thefollowingaddresseshadpermanentdeliveryerrors"Thefollowingaddresseshadpermanentdeliveryerrors"/"Thefollowingaddresshadpermanentdeliveryerrors":Eitherofthesesentencesareusuallyfollowedbyoneormoreemailaddress(es).
Theerrormessageiseffectivelysayingthattheemailaddresseslisteddonotexist,ornolongerexist(ifyouusedtobeabletoemailtothemsuccessfully).
Youneedtogetthesendertoverballyverifywiththerecipientwhathis/hernewemailaddressis.
Mailboxisinactive(ThehostingISPishavingproblems)Atypicalerrormessagemightgolikethis:"Amessagethatyousentcouldnotbedeliveredtooneormoreofitsrecipients.
Thisisapermanenterror.
Thefollowingaddress(es)failed:XXXXXXMailboxisinactive".
ThiserrorisalmostalwaysaproblematthehostingISPwhichhoststhePOPbox(es)oftherecipient'semailaddressordomain.
Youneedtoinformtherecipientthatthereisaproblemwiththeirhostingcompany.
So,forexample,ifyouaresendinganemailtoJohn.
Doe@clara.
netandyougetthe"Mailboxisinactive"error,thenyouneedtotellJohnDoethathishostingISP,ClaraNET,arehavingproblemswithincomingemailsandthatheshouldtalktothem.
oooooooOOOOOOOooooooo
com,28-Feb-2010.
SMTPErrorCodes&SMTPStatusCodes&SMTPReplyCodesReference2010TherecomesatimeinthelifeofaComputerConsultantwhere,oneday,he/shewillhavetodealwithemailserverproblems.
Itisinevitable.
SometimestheseproblemswillbewiththeinterfacingofthemailserverwiththeISP,inparticularaninabilitytosendmail.
Aftercheckingtheusualsuspectssuchaslackofconnection(yourbroadbandlineisdead),faultyrouter,firewallproblems,DNSproblems,oranincorrectSMTPservername(thankstosomecleverISPchangingitsSMTPservernamewithoutinforminganyone–ithappens!
!
),youwilllikelystartdelvingalittledeeperbycheckingifyouremailserverreportsanyerrors.
Dependingontheactualproblemitisencountering,yourmailservermaynotbeabletoprovidedetailedhelponhowtoresolvetheproblem,andmayinsteadonlybeabletoprovideyouwithanSMTPStatusCodeinyourserver'slog(thesecodesarealsoknownasSMTPErrorCodesorSMTPReplyCodes),oremailswillbereturnedtothesenderwitherrortext.
Aclassicreplymightbe,forexample,"SMTPerrorfromremotemailserverafterendofdata-:550Error:Messagecontentrejected",or"SMTPerrorfromremotemailserverafterRCPTTO,5505.
1.
1Userunknown"or"SMTPError:Datanotaccepted"or"SMTPError:Thefollowingrecipientsfailed".
Itisjustforsuchcasesthatwehaveproducedthisdocument(weuseittoo!
!
).
Whatdoes550meanWhatdoes5505.
1.
1mean(or,shortened,whatdoes511mean)Whatdoes"Datanotaccepted"meanSo,usethisdocumentasaquickreferencetocommonSMTPstatuscodesorSMTPerrorcodesforSMTPmailserverssuchasAAMailServer,Alt-NMDaemon,ArGoSoftMailServer,AxigenMailServer,BarracudaSpamFirewall,CMail,CMailServer,E-MailAnywhere,FTGate,GMSMail,InternetAnywhere,KerioMailServer(KMS),LotusNotes,MailEnable,Mailman,MailMax,Mailtraq,MerakMailServer,MicrosoftExchange(ExchangeServer2003NDR,Non-DeliveryReport,errorcodes),NovellGroupWise,Qmail,PostCastServer,PostConf,PostFix,PowerMTA,QKSMTPServer,RockliffeMailSite,SendMail,SquirrelMail,SurgeMail,TFSSecureMessageServer,VisNeticMailServer,WinMail,Zimbra,oranyotherSMTP/ESMTPstandardscompliante-mailMTA.
Note:thefollowinglistofSMTPreplycodescanalsobeusedtotroubleshootEudoraorFoxMailemailproblems,Outlookerrorcodes,OutlookExpresserrorcodes(Windows2000/XP),WindowsMailErrorCodes(Vista),Thunderbirdproblems,orotheremailprogramproblemswhenthoseprogramssendandcollectemailsdirectlytoandfromtheInternetasopposedtothroughacorporateemailsystem.
Theerrorcodesreturnedarethesame.
Finally,therearenobettertoolsforresolvingcomplexSMTPerrorsituationsthantheWHOIS,NameServerLookup,TraceRoute,andPINGtoolsofourownTheUltimateTroubleshooteravailableonourAnswersThatWork.
comwebsite–thatishowweourselvesquicklysolvecomplexSMTPerrorsituations.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage2of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean101–Cannotopenconnection(alsocalledSMTPError1.
0.
1)SMTPError101:TypicallyyourSMTPserveroremailprogramisunabletoevenstartanSMTPsession.
Typicalreplieswillbe"SMTPError101,Erroropeningconnection"or"SMTPError101,cannotopenSMTPstream".
AllSMTPError101errorsusuallypointtoaconfigurationproblem,suchasanincorrectlyspeltSMTPserver,oranIPaddressthatdoesnotexist,oranSMTPportthatdoesnotexistorwhichtherecipientwillnotacceptSMTPconnectionson,orsomeotherprocessisalreadyusingthedefaultSMTPport,port25.
111–Connectionrefused(alsocalledSMTPError1.
1.
1)SMTPError111:TypicallyfromLinuxbasedemailsystemssuchasSquirrelMailandMailman.
Themessagewillusuallygolikethis:"Connectionrefused,111Can'topenSMTPstream".
AllSMTPError111errorsusuallypointtoaninabilityofyourservertocommunicatewiththeremoteSMTPserver(eithertherecipient'sSMTPserveroryourISP'sSMTPserver)ortoaLinux/SMTPsoftwareconfigurationproblem,typically/etc/hostsnotbeingworldreadable,oranewlyinstalledorreconfiguredfirewallpreventingconnectiontotheremoteSMTPserver,orincorrecthostnamesand/ordomains(e.
g.
doesyoursendinghostnamematchyourIPaddressinareverselookup),oreximnotrunning.
Telnetandlogsshouldhelpyouhomeinontheproblem.
211–SystemStatusmessageorSystemHelpReply(alsocalledSMTPError2.
1.
1)SMTPError211:SMTPstatus211prefacesamessageabouttheMailServerstatusoraSystemHelpreplytotheuserrequestinghelpinformation.
YoumightforexampleissueacommandtothemailservertodisplayalistofcommandsyoucanuseandtheserverreplieswithanSMTPReply211followedbythelistyourequested.
214–HelpReplymessage(alsocalledSMTPError2.
1.
4)SMTPError214:SMTPstatus214isusuallyinreplytothe"HELP"command.
Itdisplaysinformationabouttheserver,usuallyaURLtotheFAQpageoftheSMTPsoftwarerunningontheserver.
Asaresultthis"error"isnormallycalledareply,asinSMTPReply214.
220–serviceisrunning(alsocalledSMTPError2.
2.
0)SMTPStatus220:Thisisnormallythefirstmessageyouwillgetbackfromtheserver.
Itmeansthemailserviceisrunning(ie.
yourmailserverisrunning).
Itwillnormallycontainawelcomemessageand/orthetitleoftheSMTPsoftwareand,sometimes,theversionnumberofthemailserversoftware.
SMTPReply220iseffectivelya"HiThere,Ihavejustthissecondfinishedstartingup–Iamreadytogoandatyourcommand"informationalmessage.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage3of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean221–Thedomainserviceisclosingthetransmissionchannel(alsocalledSMTPError2.
2.
1)SMTPError221:Theserverisendingthemailsession–itisclosingtheconversationwiththeISPasithasnomoremailtosendinthissendingsession.
SMTPStatus221isoftenmisconstruedasanerrorcondition,whenitisinfactnothingofthesort.
Themailserverissimplytellingyouthatithasprocessedeverythingitwasgiveninthisparticularsession,anditisnowgoingbackintowaitingmode.
BecauseSMTPstatus221isoftenmisinterpreted,withsomemailserverstheNetworkAdministratorshavechangedthedefaulttextofSMTPReply221tosomethingmoremeaningfulandlessalarming.
Forexample,atypicalSMTPreply221mightsay"221Goodbye"or"221Closingconnection",orthemostirritatingonewe'veseen"221Bye",Arrrgghh–canyoublameanyoneforthinkingtheremightbeaproblemOfcoursenot!
SosomeNetworkAdministratorsarethesedaysbeingquiteimaginativebychangingthedefaulttextofSMTPreply221tomoreuserfriendlymessageslike:"221Thankyouforyourbusiness"(Ilovethatone!
),or"221Allmessagesprocessedsuccessfullyinthissession,SMTPconnectionisclosing".
250–RequestedmailactionOKcompleted(alsocalledSMTPError2.
5.
0)SMTPStatus250:Themailserverhassuccessfullydeliveredthemessage!
ThisisthebestSMTPreply(250)toreceive-yourmessagehasbeenacceptedandtransmittedOK!
Yippee.
250iseffectivelyastatuscoderatherthananerrorcode–thereisnosuchthingasanSMTPerror250.
251–Usernotlocalwillforward(alsocalledSMTPError2.
5.
1)SMTPStatus251:TheemailaccountisnotlocaltotheISPserverbuttheISPserverwillaccepttheemailandwillforwardit(theserverwillRELAYyourmessage,thisisthemostcommonactionforISPMailservers–therecipientwillseeyourISPinthemailheaderasoneofthefirsthopsonthewaytotherecipient'semailsystem).
SMTPError251isthereforemoreofaninformationalmessagefortechnicianstrackinghowamessagereacheditsdestination.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage4of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean252–CannotVRFY(verify)theuser–theserverwillacceptthemessageandattempttodeliverit(alsocalledSMTPError2.
5.
2)SMTPStatus252:Theuseraccountappearstobevalidbutcouldnotbeverified,howevertheserverwilltrydodeliverthemessage.
TherearesometimescircumstanceswhereanemailaddressappearstobevalidbutcannotbeverifiedasdefinitelyvalidduringtheSMTPsessionbetweenthesendingserver(yourserver)andthenextservertoacceptyourmessage.
Thiscanhappenforexampleinverylargecorporationwherethefirstemailreceivingservermightonlybeanemailexchangerserver,agatewayservertotheeventualserverwhichholdstheusermailboxesandwhichcanverifyiftheintendedrecipientexistsinthatorganization.
WhenthishappensthegatewayserverwillreplywithanSMTPError252tellingyoursendingserverthatitcannotverifytheuserpartoftheemailaddress,thatthedomainpartisOK,andthatitwillforwardyouremailtoaserverwhichcandothecheckingandeventuallydelivertotheusermailboxifitexists.
354–Startmailinputendwith.
,or,asalesscrypticdescription–"FROMandTOinformationreceived,nowpleaseprovidemessagebodyandmarkitsendwith.
"(alsocalledSMTPError3.
5.
4)SMTPError354:ThisisnormallyinresponsetotheDATAcommand.
TheserverhasreceivedtheFromandToinformationandisnowaskingforthe"MessageBody",themainpartofthemessagewhichshouldbeendedbytwoblanklinesseparatedbyadot(period).
Therefore,onreceivinganSMTPReply354thesendingservershouldsendthebodyofthemessagetothereceivingserverandindicatetheendofthemessagebodywith.
(notethefullstopbetweenthetwoCarriage_Return-Line_Feed's).
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage5of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean420–Timeoutcommunicationproblemencounteredduringtransmission.
ThisisaNovellGroupWiseSMTPerror(alsocalledSMTPError4.
2.
0)SMTPError420:InourexperienceonlyNovellGroupWiseserversusethiserror(weuseGroupWise!
).
YouwillgetaGroupWiseGWIA(GroupWiseInternetAgent)420TCPWriteErroror420TCPReadErroriftherearecommunicationproblemsduringtransmissionoftheactualmessageafterthesendingandreceivingservershaveactuallyconnected.
Asmallnumberof420SMTPerrorsisnormalasoccasionalpeaksofInternetusagemaydelaythetransmissionofanemailwithattachmentsomuchthatatimeoutoccurs.
WhenatimeoutoccursonaGWIAsend,themessageisqueuedupinthe\WPGATE\DEFERdirectoryforprocessingatalatertime(asdefinedinConsoleOneorGWIA.
CFG).
Ifyouexperience420errorsonlywithspecificrecipientthenitisquitelikelythattherecipient'santispamfirewalldoesnotlikeyourserver,yourserver'sexternalIPaddress,orthatyourserver'sHELOcommandusesanoutboundidentificationthatdoesnotmatchyourserver'sexternalIPaddress(checkthatyoursendingdomain'sDNSissetupcorrectly).
InanidealworldawellbehavedrecipientservershouldreallybeissuingyourGroupWiseserverwitha554errorratherthantimingoutandcausingtheGroupWiseGWIAtofaultwitha420error.
Ifyouexperiencetoomany420errorswithallemailcommunications,thenyouhaveaphysicalcommunicationproblemsomewhere.
Thiscouldbeyourserver'snetworkcard,thenetworkpointthatyourserverispluggedinto,yourswitch(es),yourrouter(s),yourfirewall,oryourInternetline–problemscausedbyrouterswithdifferentMTUsizesisaclassicissue.
Unlessthelogsofallthosevariousproblempointscangiveyouaninstantanswer,theonlywayyouwillgettothebottomoftheproblemistouseapackettracingandinspectionprogramlikeEtherealorWireshark,itssuccessor,ifyou'rerunningGroupWiseonaWindowsorLinuxserver;onNetWareyouronlychoiceisPacketScanwhichyoucangetherehttp://support.
novell.
com/docs/Readmes/InfoDocument/2967287.
html.
Inthefinalanalysis,ifthetracingofpackets,andthechangingofhardwaredoesnothelpthendonotdiscountaslightlyfaultyharddiskbeingthecauseofallyourproblems(evenifyourRAIDcontrolleroryourharddisktestingsoftwaredoesnotdetectanyproblem!
).
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage6of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean421–Servicenotavailable–thesendingemailprogramshouldtryagainlater(alsocalledSMTPError4.
2.
1)SMTPError421:TheMailtransferserviceisunavailablebecauseofatransientevent.
SMTPreply421canbecausedbymanythingsbutgenerallyindicatesthatthemailserverwhichreturnsthisstatuscodeiscurrentlyunavailablebutmaybeavailablelater.
Forexample,theserveradministratormayhavestoppedthemailservicetotroubleshootaproblem,orthemailserverisrightinthemiddleofrebooting,orthemailserveriscurrentlyprocessingtoomanyincomingmessagesorincomingrequests,etc.
.
.
.
Note:"MailServer"inthiscasecanbeanyofthemailserversonthemessage'sroute–thesendingserver(yourserver),theISPSMTPserver,ortherecipient'smailserver.
Clearly,ifyourepeatedlyreceiveanSMTPstatus421thentheproblemisnolongerofatransientnatureandyouneedtoinvestigateorinformtherelevantnetworkadministrator,ISPtechsupport,ortherecipient.
422–Therecipient'smailboxisoveritsstoragelimit(alsocalledSMTPError4.
2.
2)SMTPError422:Eithertherecipient'smailboxisoveritsstoragelimitorthemessagedeliverydirectory(folder)ontherecipient'smailserveriscurrentlyoverasizelimitimposedbytheNetworkAdministrator(e.
g.
possiblyasaresultofthemailserverhavingbeendownforsometime,havingbeenrepaired,andcurrentlyintheprocessofcollectingthousandsofqueuedupmessages).
431–Therecipient'smailserverisexperiencingaDiskFullcondition(alsocalledSMTPError4.
3.
1)SMTPError431:Therecipient'smailserverisexperiencingaDiskFullerrorcondition,oranOutofMemory(toomanyfilehandles)errorcondition(MicrosoftExchange).
432–Therecipient'sExchangeServerincomingmailqueuehasbeenstopped(alsocalledSMTPError4.
3.
2)SMTPError432:ThisisanSMTPstatusresponsespecifictoMicrosoftExchangeServer.
Itindicatesthattherecipient'smailqueueontheirExchangeServerhasbeenstopped(frozen),probablywhiletheNetworkAdministratortroubleshootssomeproblem.
441–Therecipient'sserverisnotresponding(alsocalledSMTPError4.
4.
1)SMTPError441:Thisisanerroremanatingfromyourserverindicatingthattherecipient'sserverisnotresponding.
Yourserverwillautomaticallytryagainanumberoftimes–howmanydependsonhowyourserverhasbeenconfigured.
442–Theconnectionwasdroppedduringtransmission.
(alsocalledSMTPError4.
4.
2)SMTPError442:Yourserverstarteddeliveringthemessagebuttheconnectionwasbrokenduringtransmission.
Thismaybeanunusualtransienterror–however,ifitkeepshappeningyoushouldinvestigatepossibleproblemswithyourserver'snetworkcard,yourInternetrouters,processeshoggingtheresourcesofyourserver,andanythingelsewhichcouldresultinanetworkconnectionbeingbroken.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage7of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean446–Themaximumhopcountwasexceededforthemessage(alsocalledSMTPError4.
4.
6)SMTPError446:Themaximumhopcountwasexceededforyourmessage.
Themostlikelycauseofthiserrorstatuscodeisthatyourmessageisloopinginternallyonyourserver,internallybetweentwoofyourorganisation'sservers,or,sometimes,loopingbetweenyourserverandtherecipient'sserver.
447–Youroutgoingmessagetimedout.
(alsocalledSMTPError4.
4.
7)SMTPError447:Youroutgoingmessagetimedoutbecauseofproblemswiththereceivingserverwhoobjectedtoyourmessage.
Typicallythereisaproblemwiththemessageheader(suchastoomanyrecipients,inmostcases,oraprotocoltimeoutbetweenthetwoservers).
449–Routingerror(alsocalledSMTPError4.
4.
9)SMTPError449:ThisisaMicrosoftExchangeServerspecificerrorcode.
AsperMicrosoft'sdocumentationthiserrorcodeisreturnedwheneitherofthefollowingconditionsoccurs:anSMTPconnectorisconfiguredtouseDNSwithoutasmarthostandalsousesanon-SMTPaddressspace(e.
g.
X.
400),orAmessagewassenttoarecipientwhowasidentifiedasamemberofaroutinggroupthatwasdeleted.
MicrosoftrecommendsusingtheWinRoutetooltotroubleshootthiserror(MicrosoftKnowledgebasearticle281382)450–Requestedactionnottaken–Themailboxwasunavailableattheremoteend.
AsecondarySMTPerrorcodemayfollow"450"torefinethereasonforthefailuretotransmitthemessage,e.
g.
"SMTPError450(alsocalledSMTPError4.
5.
0)SMTPError450:Theservercouldnotaccessthemailboxtodeliverthemessage.
Thiscouldbecausedbyaprocessontheremoteservertidyingupthemailbox,ortheremotemailboxcouldbecorrupt,ortheremotemailboxmaybestoredonanotherserverwhichiscurrentlyoffline,orthenetworkconnectionwentdownwhilesending,ortheremotemailserverdoesnotwanttoacceptmailfromyourserverforsomereason(IPaddress,blacklisting,etc.
.
).
IngeneralSMTPError450isatransienterrorattheremoteend(thedestination),oratoneoftheroutersorserversenroutetotheremoteend,andshouldinduceyourmailservertoretryafterit'spresetretryinterval.
ExampleofanSMTPError450replymessage:"450Pleasetryagainlater",oraclassicNovellGroupWise450statusmessage:"Themessagethatyousenthasbeendelayed.
Thereasongivenforthedelay:450Hostdown(relay.
clara.
net)".
SMTPError450isoftenfollowedbyasecondSMTPerrorcodetorefinethereasonfortheemailnotreachingitsdestination.
Forexample:"SMTPError4505.
2.
3MsgSizegreaterthanallowedbyRemoteHost".
WhenthatisthecaseandIftheerrormessageisnotasclearlywordedasinthisexample,thensimplysearchthisdocumentforthesecondaryerrorcode.
InthiscasesearchingthisdocumentforSMTPError523orSMTPError5.
2.
3wouldyieldanexplanationidenticaltothewordingabove.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage8of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean451–Requestedactionaborted–Localerrorinprocessing.
orhasrecentlysentspam(alsocalledSMTPError4.
5.
1)SMTPError451:TheactionhasbeenabortedbytheISP'sserver.
"Local"referstotheISP'sserver.
ThiserrorisusuallyduetooverloadingattheISPfromtoomanymessagesortransientfailures.
Typicallysome[hopefully]temporaryeventpreventsthesuccessfulsendingofthemessage.
Thenextattempttosendbyyourservermayprovesuccessful.
Ifthiserrorkeepsoccurringtothepointthatithaseffectivelylostitstransientnatureandhasbecome.
.
.
.
.
frequent(!
!
),thentheproblemisatyourendandyoushouldcheckyourownmailserver(ifyouemailoutofacorporatenetwork),communicationsonyourside(router,servernetworkcard),orinformyourISPifyourmailserverrelaysthroughyourISPorifyouareahomeuseremailingoutthroughOutlook,OutlookExpress,WindowsMail,orsimilaremailprogram.
ExampleoftypicalSMTPError451returnmessages:"SMTPerror451Unabletocompletecommand,DNSnotavailableortimedout"or"451Domainofsenderaddressdoesnotresolve"or"451ErrorgettingLDAPresultsinmap",or"4514.
7.
1Greylistinginaction,pleasecomebackin00:02:00[minutes]".
WiththeoriginalSMTPstandardshavingbeeninventedbeforespambecausethescourgeoftheInternet,therearenoSMTPerrorcodesdedicatedtoanti-spamerrors.
Asaresult,SMTPError451isnowincreasinglyalsousedtoindicatethatamessagehasbeenrejectedbytheremoteserverbecauseofanti-spammeasures.
Atypicalerrormightbe,forexample:"SMTPerrorfromremotemailserverafterendofdata,host:451hasrecentlysentspam.
Ifyouarenotaspammer,pleasetrylater.
".
Ifallanti-spamrelatedSMTP451errorsareasdescriptiveastheoneabove,thentheerroritselfwilltellyouwhatyouneedtodo.
Asageneralrule,however,youwillmosttimesneedtotakesomemeasurestohaveeitheryourserver,oryourISP'sserver,takenoffsomeInternetblacklistusedbytherecipient.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage9of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean452–Requestedactionnottaken–Insufficientstorage.
(alsocalledSMTPError4.
5.
2)SMTPError452:TheISPserver'sdisksystemhasrunoutofstoragespace,sotheactionhadtobecancelled.
UnlessyouarewithanISPwhichissoslackthattheyhavenotimplementedDiskFullAlerts,thiserrorusuallyindicatesthatyourISP'smailserverisoverloadedfromtoomanymessages.
ThiscanhappeneventothebestISPswhen,forexample,therehavebeenproblemsandnoneoftheISP'scustomerscouldsendmail;assoonastheproblemsarefixedthereisalmostalwaysasituationwherethousandsofusersandorganizationsaretryingtosendmailallatthesametime,andthosenumberscanoccasionallyresultintheISP'smailservers'harddiskstemporarilyfillingup,withSMTPError452beingtheresult.
Thenextattempttosendbyyourservermayprovesuccessful.
SMTPError452:MostISPsmailserversimposeamaximumnumberofconcurrentconnectionsthatclient'smailserverscanattempttomake,andtheyusuallyalsohavealimitonthenumberofmessagesthataresentperconnection.
Withbusinesscustomersthesemaximumsarerarelyreached,ifever.
Nevertheless,Ifyouhavealotofmessagesqueuedup,forexampleasaresultoftheconnectiontoyourISPgoingdownforasignificantamountoftime(andyouhavehundredsofusersinyourorganization,orithappenedjustasyouwereabouttosendthatlargemailshot!
),therecouldbeasituationwheretheoutputofmessagesfromyourservergoesoverthemaximumnumberofmessagesperconnectionallowedbyyourISP.
ThisisanothercasewheretheISP'sservermayissuea452SMTPerror.
Asabove,thenextattempttosendbyyourservermayprovesuccessful.
SMTPError452:Thiserrorcanalsobeindicativeofaproblemonyourownmailserver.
HereisanexampleofanSMTP452error:""452Outofmemory"465–CodePageunavailableontherecipientserver(alsocalledSMTPError4.
6.
5)SMTPError465:ThisisanExchangeServer-specificerrorcode.
Thiserrorisreturnedbytherecipient'sserveriftheincomingemailspecifiesaCodePagethatisnotinstalledontherecipient'sserver,normallybecausenotalllanguagefileswereinstalledontheserverduringeithertheinstallationofWindowsorofExchangeServer.
Update:in2010weareseeingothermailserverprogramsandwebapplicationsnowusingSMTPError465.
ForexampletheosTicketproductwillreturn"465SMTP:Invalidresponsecodereceivedfromserver"iftheSMTPserveryouareusinginyourconfigurationofosTicket,requiresauthenticationandyouhavesetuptheauthenticationincorrectly.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage10of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean471–Thisisalocalerrorwiththesendingserverandisoftenfollowedwith"Pleasetryagainlater"(alsocalledSMTPError4.
7.
1)SMTPError471:Thisisalwaysalocalerrorwithyourownmailserver.
SMTPError471(or4.
7.
1)isusuallytaggedontoaprimarySMTPerrorcode,forexample"SMTPError4504.
7.
1",or"SMTPError4514.
7.
1",or"SMTPError5504.
7.
1";example:"4514.
7.
1Greylistinginaction,pleasecomebackin00:02:00[minutes]".
InallthecasesthatwehaveseenSMTPError471isusuallycausedbyanti-spamorvirusscanningsoftwareonyourserver(thesendingserver)gettingintoproblemsthroughabuginthesoftware,orbecauseofabadautomaticupdatefromtheantivirus/anti-spammanufacturer,becauseoflackofmemoryonyourserver,orbecauseofharddiskproblems.
500–Syntaxerrorcommandnotrecognized.
(alsocalledSMTPError5.
0.
0)SMTPError500:ThelastcommandsentbyyourserverwasnotrecognizedasavalidSMTPorESMTPcommand,orisnotformattedinthewaytheserverexpected.
Thisincludessituationswherethecommandistoolong.
Notethatcommandsthatarerecognized,butnotimplemented,arehandledbydifferentstatusmessages(see502and504).
Note:A"500unrecognizedcommand"serverresponseisoftenacaseofantivirussoftwareinterferingwithincomingand/oroutgoingSMTPcommunications.
Readyourantivirus/firewallsoftwaredocumentationthoroughlytosolvetheproblem.
501–Syntaxerrorinparametersorarguments(e.
g.
invalidemailaddress)Cansometimesalsobeindicativeofcommunicationproblems(alsocalledSMTPError5.
0.
1)SMTPError501:Thecommandwascorrectandrecognised,buttheparameters(thearguments,e.
g.
emailaddress)werenotvalid.
Forexample,thefollowingemailaddresswilldefinitelygiveanSMTPError501withmostmailservers,happy\_larry@hotmail.
com,as"\"isnotallowedinemailaddresses,whichmakesthisemailaddressinvalid.
InthevastmajorityofcasesSMTPError501iscausedbyinvalidemailaddresses.
Forexample,atypicalreturnerrormessagemightbe:"doesnotlikerecipient.
Remotehostsaid:501InvalidAddress".
Incaseswheretheerrorisnotcausedbyaninvalidemailaddress,anSMTPError501,particularlyifrepeated,canbeindicativeofcommunicationsproblems,suchasanoisyline,intermittentdropsinnetworkconnections,etc.
.
.
502–Commandnotimplemented.
(alsocalledSMTPError5.
0.
2)SMTPError502:Thecommandorfunctionissuedbyyourmailserverisvalidbuthasnotbeenactivated(typically,itisnotsupportedonthisparticularserver).
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage11of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean503–Badsequenceofcommands.
orThismailserverrequiresauthentication(alsocalledSMTPError5.
0.
3)SMTPError503:IntheoriginalstandardsSMTPStatus503indicatesthatthecommandshavebeensentinthewrongorder,forexampleyourmailserverhassentthe"Hello"commandbeforesendingthe"Mail"command.
Thiscanoftenbecausedbyadropinnetworkconnectionjustasyourserverwassendingacommand,resultingintheISP'sservernotreceivingitandconsequentlynotunderstandingthecommandthatfollowedit.
Note:thiserror,particularlyifrepeated,canbeindicativeofcommunicationsproblems,suchasanoisyline,intermittentdropsinnetworkconnections,etc.
.
.
SMTPReplyCode503isnowadaysmoreoftenanindicatorthattheSMTPserveryouaretryingtouserequiresauthenticationandyoutriedtosendamessagewithoutauthentication(username+password).
ThisSMTPError503ispermanentinthattheSMTPserverwillnotloganyerrorsinitsloganditwillnotretry–youwillhavetoresendtheemailusingauthentication.
Exampleofsuchanerror:"SMTPError(state13):503Thismailserverrequiresauthenticationwhenattemptingtosendtoanon-locale-mailaddress.
Pleasecheckyourmailclientsettingsorcontactyouradministratortoverifythatthedomainoraddressisdefinedforthisserver.
".
504–Commandparameternotimplemented.
(alsocalledSMTPError5.
0.
4)SMTPError504:Thecommandandparameterarebothvalid,buttheparameterisnotimplementedontheISPserver,oranadditionalparameteroractionismissing.
Forexample,anoftenencounteredSMTPError504is:"504Needtoauthenticatefirst".
IfyouarereceivingthiserrorinaMicrosoftExchangeServerenvironmentwheretheerrorshowsupintheApplicationLogasEventID7004or7010,thenreadthisMicrosoftKnowledgebasearticlehttp://support.
microsoft.
com/kb/843106.
510–BadEmailAddress(alsocalledSMTPError5.
1.
0)SMTPError510:Bademailaddress.
Thisstatuscodeisgeneratedbythesender'slocalmailserver.
Iftheemailwasaddressedinternally,thenitmeansthattheaddressee,aswrittenintheemail'sTO,CC,orBCCfields,doesnotexistinyourorganization'semailsystem.
Iftheemailwasaddressedexternally,thentherecipient'semailaddresswasmisspelt.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage12of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean511–BadEmailAddress(alsocalledSMTPError5.
1.
1)SMTPError511:Bademailaddress.
Thiserrorissimilartoerror510andaswitherror510,thisstatuscodeisgeneratedbythesender'slocalmailserver.
Iftheemailwasaddressedinternally,thenitmeansthattheaddressee,aswrittenintheemail'sTO,CC,orBCCfields,doesnotexistinyourorganization'semailsystem.
Iftheemailwasaddressedexternally,thentherecipient'semailaddresswasmisspelt.
512–Thehostserverfortherecipient'sdomainnamecannotbefound(DNSerror)(alsocalledSMTPError5.
1.
2)SMTPError512:ThisSMTPreplycodeisreceivedwhenoneoftheserversonthewaytothedestinationisunabletoresolvethedomainnameofarecipientemailaddress.
Saiddifferently:oneoftheserversonthewaytothedestination,includingyourserveroryourISP,hasaDNSproblemor,possiblycorrectly,doesnotlikeoneoftheemailaddressesinthemessage'sTO,CC,andBCCfields.
Thefirstcheckyoushouldperformtoresolvea5.
1.
2replycodeistocheckalltherecipientemailaddressesforincorrectdomainnames(misspeltdomainnames,or,maybe,totallynon-existentdomainnames)–remember,errorcode512isveryspecificallyanerrorwiththedomainnameofoneoftherecipientemailaddresses.
Youcancalltherecipient(s)orusetheWHOIStoolofTheUltimateTroubleshooter.
Ifalltherecipientemailaddressescheckoutasregardsthedomainpartoftheemailaddresses,thenoneoftheserversonthewaytotherecipient(s)hasDNSproblems–usuallythiswillbeoneofthefirst2serversinthechain,yourownmailserver(oryournetwork)oryourISP'smailserver.
ExamplesoftypicalSMTPerror512messages:"5.
1.
2-Baddestinationhost'DNSHardErrorlookingupdomain",or"SMTPError5505.
1.
2Hostunknown–hostcannotbefound",orhowaboutthisfantasticallyinformativeerrormessage"5.
1.
2Themessagecouldnotbedeliveredbecausetherecipient'sdestinationemailsystemisunknownorinvalid.
Pleasechecktheaddressandtryagain,orcontactyoursystemadministratortoverifyconnectivitytotheemailsystemoftherecipient.
".
Insummary:mostSMTPerror512conditionsarecausedbymisspellingsofthedomainnamepartofarecipientemailaddress.
However,withtheproliferationofspam,error512isalsooftenencounteredbyautomatic"out-of-office"repliestojunkmailbecausethedomainnamesusedbyjunkmailareoftenbogusdomainnames.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage13of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean513–Addresstypeisincorrect(mostmailservers)orRelayingdeniedorAuthenticationrequired(asmallpercentageofmailservers)(alsocalledSMTPError5.
1.
3)SMTPError513:Thisstatuscode(fromthesender'smailserver)isusuallysymptomatic,inanExchange+Outlookenvironment,oftheuser'sOutlookContactshavingbeenimportedfromanothersystemorPSTandwheresomeoftheaddressesarenotdefinedcorrectly.
Or,inanyenvironmentitissimplythattheend-usersimplydidentertheemailaddresscompletelywrongly,suchascopyingitfromawebsiteandnotreplacing"at"with"@",e.
g.
:John.
DoeatUCLA.
edu(whichshouldhavebeenJohn.
Doe@UCLA.
edu),orJohn.
Doe@UCLA.
edu"(",quotes,isnotallowedinemailaddressesandisoftenincludedinerrorasaresultofcopyingandpastinganemailfromsomewhere).
Theusershouldcheckalltherecipientaddressesintheemail,includingthosethatwereinsertedfromContacts.
Note:theSMTPreplycode5.
1.
3isoftenasecondaryreplycode.
Somemailservers,forexample,mightreply"SMTPerror5015.
1.
3Invalidaddress",or"SMTPerror5535.
1.
3Useraddressrequired!
",or"SMTPerror5015.
1.
3Badrecipientaddresssyntax",or"SMTPerror513RelayingDenied-Cannotsende-mailstosomeaddresses",orthisexcellentlyinformationalExchangeServer2007error(thewholeerrormessageisingreenbelow):"SMTPerror5505.
1.
3STOREDRV.
Submit;invalidrecipientaddress.
Deliveryhasfailedtotheserecipientsordistributionlists:Theformatoftherecipient'se-mailaddressisn'tvalid.
Avalidaddresslookslikethis:username@microsoft.
com.
MicrosoftExchangewillnottrytoredeliverthismessageforyou.
Pleasecheckthee-mailaddressandtrysendingthemessageagain,orprovidethefollowingdiagnostictexttoyoursystemadministrator.
5.
1.
3:Theformatoftherecipiente-mailaddressisnotvalid.
ValidSMTPe-mailaddressescancontainonlyletters,numbers,hyphens,periods,andonlyone@symbol.
Troubleshooting:VerifythattheSMTPaddressoftherecipientisformattedcorrectlyandresendthemessage.
"SMTPError513isalsousedbyasmallpercentageofmailserverstoindicateacompletelydifferenterror,namelythatyouneedtoauthenticatetothemailserverbeforebeingabletosendyourmessage(SMTPauthentication).
Atypicalerrormessagemightbe:"SMTPerror553Authenticationisrequiredtosendmailasusername@ispdomainname.
com".
Insuchcasesyousimplyneedtoconfigureyourmailserver,oryouremailprogramtosendemailswithSMTPauthentication.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage14of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean523–TheRecipient'smailboxcannotreceivemessagesthisbig(alsocalledSMTPError5.
2.
3)SMTPStatus523:Thiserrorwillbereceivedwhenthetotalsizeofthemessageyouhavesent(ie:message+allofitsattachments)exceedsthesizelimitsontheRecipient'sserver.
Manycompaniesimplementthegoodpracticeofconfiguringtheirserverswithlimitsonthesizeofemailstheycanreceivetopreventtheirsystemsrunningoutofspaceasaresultofaspamattackwherethespamemailscontainlargeattachments,orasaresultofvalidbutnotverytechnicallysavvysenderssendingenormousscans(throughnotknowingthatscanningat1200dpiratherthantheusuallyperfectlyusableandacceptable300dpi,willcreatehumongousattachments).
Checkthesizeoftheemailyousent,and,specifically,thesizeoftheattachmentsyouincluded,andconsidersplittingyouremailintosmalleremails.
Ifthatdoesnotwork,checkwiththeRecipientthemaximumsizeofemailtheycanreceive,andifthatisstillprohibitivethenconsiderFTParrangementsbetweenyouandtherecipient.
SMTPError523isoftenasecondarySMTPerrorcoderatherthanaprimaryerrorcode,asinthefollowingexamples:"SMTPError4505.
2.
3MessageSizegreaterthanallowedbyRemoteHost"or"SMTPError5525.
2.
3Datasizeexceedsmaximumpermitted"or"SMTPError5525.
2.
3Messageexceedsmaximumfixedsize",andsoon.
.
.
.
550–Requestedactionsnottakenasthemailboxisunavailable.
(alsocalledSMTPError5.
5.
0)SMTPError550:Thisresponsecanbecausedbyquiteafewsituations.
SMTPError550willbereturnedbymanyserversIftherecipientemailaddresssimplydoesnotexistontheremoteside(youwilloftenget"550Invalidrecipient"or"550Useraccountisunavailable"or"doesnotlikerecipient-550Addressrejected"or"550Nosuchuserhere"or"550NotourCustomer"or"550Accountnotavailable"or"Remotehostsaid:550–Barack.
Obama@ThisCompany.
com,thisTHISCOMPANY.
COMMailboxDoesNotExist–Givingup").
Inthiscasethesenderoftheemailneedstocontacttherecipientverballytogetthecorrectemailaddress.
SMTPError550willsometimesalsobereturnedbytherecipient'santi-spamfirewallif,forexample,theanti-spamfirewalldoesnotlikethesender(typicallybecausethesenderneedstobewhitelisted).
AtypicalexampleofanSMTPError550returnmessagebyananti-spamfirewallmightbe:240.
240.
240.
240doesnotlikerecipient.
Remotehostsaid:550-VerificationfailedforAnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage15of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeanJohn.
Doe@YourDomain.
com550-Previous(cached)calloutverificationfailure550SenderverifyfailedGivingupon240.
240.
240.
240.
SMTPError550willalsobereturnediftheuser'smailboxisnotlocalandMailRelayisnotenabled,orthesendingaddressisinvalid(thelatterisaway,bytheremoteserver,tocontrolspam).
OthersituationsofSMTPError550includesendingmailtorecipientsoutsideofyourdomainwherethisisnotallowed.
SMTPError550isalsoreturnedwhenyouareattemptingtosendthroughaserverwhichrequiresSMTPauthenticationandyouhavenotsuppliedcredentials(ie.
yourmailserver,oremailprogram,isattemptingtosendwithoutSMTPauthentication)YetanothersetofcircumstanceswhereanSMTPerror550mightbeissuedincludeanincorrectFromaddresswhenusedwithanISPwhereyoucansendmailonlyiftheFromaddressisfromadomainthattheyhostforyou(atthetimeofwriting,September2008,BritishTelecomintheUKissuchanISP–youhavetonotifythemthroughalengthy,ridiculous,andalmostsouldestroyingprocedure,involvingprovingthatyouownthedomain,forthemtoallowyoutosendemailsfromadomainnamethattheydonothostforyou).
AnothercaseofSMTPError550iswhentherecipient'sserverisdown(orcannotreceivemailatthistime)andtheISP'sserverswillretryperiodicallyforalimitedamountoftime(thisisoftenaccompaniedbyareturnmailfromyourISPinformingthesenderoftheemailofjustthatsituation).
AnothercaseofSMTPError550iswhentherecipient'sserverrequiresyoutomakeachangetotheTopartofyouremailtoachievesuccessfuldeliveryoftheemail(someorganizationsconfiguretheirreceivingmailserversinthiswaywhentheyhavechangedtheirdomainnameandwanttoforcethesenderstoupdatehisaddressbooks–forexample,My-Great-Company.
comhaschangeditsAnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage16of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeandomaintoMyGreatCompany.
comandyouarestillusingtheolddomainname).
YetanothersetofcircumstanceswhentheSMTPError550isreceivediswhentherecipient'smailboxhasbeensuspended.
Forinstance,theQMAILSMTPmailprogramhasanendearingwayoftellingyouaboutamailboxthathasbeensuspended:"I'mafraidIwasn'tabletodeliveryourmessagetothefollowingaddresses.
Thisisapermanenterror;I'vegivenup.
Sorryitdidn'tworkout.
:doesnotlikerecipient.
Remotehostsaid:550[SUSPEND]Mailboxcurrentlysuspended-Pleasecontactcorrespondentdirectly.
".
AnothercircumstanceofanSMTPError550iswhentherecipient'smailboxhasbeendisabled.
Thetypicalreasonsforthisarethemailboxbeingfull(theuserneedstodeletemessagesbeforenewoneswillbeaccepted)ortheusernothavingpaidabill.
Anexampleofthereplyyouwillreceiveis:"550mailboxtemporarilydisabled"551–Usernotlocalorinvalidaddress–Relaydenied.
(alsocalledSMTPError5.
5.
1)SMTPError551:Ifneitherthesendingmailaddressnortherecipient'saddressarelocallyhostedbytheserver,thentheISP'sserversmayrefusetorelaythemessageon.
SomeISPsimplementthisrestrictiontothwartspammers.
Inourview,hereatAnswersThatWork,thisisalazyandincompetentmethodoffightingspamasmostofthetimeitdoesnothingbutinconvenienceno-oneotherthantheISP'svastmajorityofconsiderateandlawabidingusers.
Inourexperiencethisusuallygoeshandinhandwithbarelycompetenttechnicalsupport.
Atthetimeofwriting,14-Sep-2008,atypicalculpritforthisisBT,BritishTelecom,intheUK.
Thewayinwhichitmanifestsitselfisasfollows:youhaveadomainthatishostedbyCrystalTech.
combutyourISPisDodgyISP.
comandyoutrytosendemailsfromyourdomaintoWhatANiceBunchOfPeopleYouAre@yahoo.
usa.
NeitheryourdomainnorYahoo.
usaarehostedbyDodgyISP.
com,asaresultyouremailisnotacceptedbyDodgyISP'smailserversandyourmailserverisreturnedanSMTPError551.
TocorrecttheproblemyouhavetocallDodgyISP.
comandaskthemtoenteryourdomainnameasanallowedsender.
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage17of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymean552–Requestedmailactionsaborted–Exceededstorageallocation.
(alsocalledSMTPError5.
5.
2)SMTPError552:Therecipient'smailboxhasreacheditsmaximumallowedsize(thisisoftenaccompaniedbyareturnmailfromyourISPormailserverinformingthesenderoftheemailofjustthatsituation).
Example:"552sorry,mailboxAlan@ThisCompany.
comisoverquotatemporarily(#5.
1.
1)".
SomemailservershaveextendedthescopeofSMTPReplyCode552byalsoincludingerrorswherethesizeoftheincomingmessageexceedsthesizelimitspecifiedbytheNetworkAdministrator,asin,forexample,"SMTPError5525.
2.
3Messagesizeexceedsfixedmaximummessagesize(7000000)",whicheffectivelysaysthattheincomingmessagewaslargerthanthe7MBlimit(7,000,000bytes)setbytheNetworkAdministratoroftherecipient'smailserver.
553–Requestedactionnottaken–Mailboxnameinvalid.
(alsocalledSMTPError5.
5.
3)SMTPError553:Thereisaninvalidemailaddressinthe"To","CC",or"BCC"fieldoftheemailmessage.
HereisatypicalSMTPError553response:"Hi.
ThisistheQMAIL-sendprogramat.
I'mafraidIwasn'tabletodeliveryourmessagetothefollowingaddresses.
Thisisapermanenterror;I'vegivenup.
Sorryitdidn'tworkout.
:doesnotlikerecipient.
Remotehostsaid:5535.
3.
0.
Addresseeunknown.
Givingup.
".
SMTPStatus553isalsosometimesreturnedbyanISPmailserver.
WhenthishappensthisisalmostalwaysbecauseyouaretryingtosendthroughaspecificISP'sSMTPserverandyetyouarenotconnectedtotheInternetthroughthatISP,e.
g.
youareconnectedtotheInternetthroughaComcastbroadbandconnectionbutyouremailprogram(OutlookExpress,WindowsMail,.
.
.
)isconfiguredtosendemailsthroughtheSMTPserverofTiscali.
Atypicalsucherrormessagemightbe:"553sorry,relayingdeniedfromyourlocation".
554–Transactionfailed.
NowadaysSMTPstatus554isinmostcasesreturnedwhentherecipientserverbelievesyouremailisspamoryourIPaddressorISPserverhasbeenblacklistedononeormoreSMTPError554:Therewasapermanenterrortryingtocompletethemailtransactionwhichwillnotberesolvedbyresendingthemessageinitscurrentform.
Somechangetothemessageand/ordestinationmustbemadeforsuccessfuldelivery.
Forinstance,YahoooftenreturnsthefollowingiftherecipientemailaddressdoesnotexistontheYahoosystems:"554deliveryerror:Thisuserdoesn'thaveaYahoo.
comaccount".
AnothertypicalYahooSMTPError554replyis:"554deliveryerror:SorryyourmessagetoAnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage18of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeanInternetblacklists.
orWithYahoo,ontheotherhand,thisusuallymeanstheemailaddressdoesnotexistorhasbeendisabled.
orWithIBM'sLotusDominothisiseitheraDominobugoraDiskFullerror(alsocalledSMTPError5.
5.
4)cannotbedelivered.
Thisaccounthasbeendisabledordiscontinued".
InthecaseofanIBMLotusDominoserverontheotherhand,thisiseitheradiskfullerror(thefirstthingtocheck),oraLotusDominobugwhichhasappearedinvariousguisesinmanyversionsofLotusDominoasfarbackas2002.
Eightyears,EightyearsandcountingandIBMstillsufferfromthisbug–themindboggles!
ClickonthislinktoreadthelatestIBMKnowledgebasearticleonthiserroratthetimeofwriting:http://tinyurl.
com/ygfqoov.
Inmostothercases,however,arecipientmailserverwillreturnanSMTPREPLY554whenitsanti-spamfirewalldoesnotlikethesender'semailaddress,orthesender'sIPaddress,orthesender'sISPserver(because,forexample,theyarelistedinanRBL)andwhereyouwillthereforeeitherneedtohavethesenderwhitelistyouintheiranti-spamprogram/appliance,or,worse,youwillneedtotakestepstohaveeitheryourIPaddressoryourISP'sservers(ifyousendmailthroughyourISP)de-listedfromoneormoreRBLs(RBL=RealtimeBlackholeList–alsocalledRealtimeBlacklistnowadays).
Forexample,a554errorreturnedbyaComcastservermightlooklikethis:"Username@comcast.
netSMTPerrorfromremotemailserverafterinitialconnection:hostmx2.
comcast.
net:554IMTA11.
emeryville.
ca.
mail.
comcast.
netwasfoundononeormoreDNSBLs,seehttp://help.
comcast.
net/content/faq/BL000010",whereDNSBLs=DNSBlacklists.
Inthiscase,therefore,ifyougetsuchamessagebackitistellingyouyourIPaddress,oryourISP'smailserverislistedononeoftheanti-spamblacklistdatabasesthatComcastusestofilteroutspamonincomingemailstoComcastmailboxes–clickthelinkprovidedintheerrormessagetoseehowyoumaybeabletoun-blacklistyourselfasfarasComcastisconcerned.
HereisanotherexamplefromtheOZEMAILISPinAustralia,"SMTPerrorfromremotemailserverafterinitialconnectiontohostmx1.
ozemail.
com.
au:554filter.
ozemail.
com.
au"–notveryinformative,asyoucansee,butthenameoftheserverreturningtheSMTPreply554iswhatgivesthisawayasOZEMAIL'santi-spamnotlikingyou:filter.
ozemail.
com.
au.
"Filter"inthenameofarecipientserverisalmostalwaysanindicationthatthatserverisananti-spamandantivirusserver.
AndhereisaTwitterexample:"SMTPerror:EmailError:RCPTTOinvalidmailserverresponse:5545.
7.
1:Recipientaddressrejected".
AnswersThatWorkTMSMTPStatuscodes–SMTPErrorCodes–SMTPReplyCodesPage19of19CopyrightAnswersThatWork.
com,28-Feb-2010.
SMTPStatusCodesWhatthemessagemaymeanNotethatSMTPError554canalsooftenbeburiedinthemiddleofSMTPError550errors.
HereisanexampleofarecipientmailserverreturninganSMTPError554becauseitsBarracudaanti-spamfirewallappliancerejectedtheemail(thecause,asshownbelow,isBarracudaReputationwhichmeansyourIPaddressoryourISP'sserverisblacklistedonBarracuda'sRBL):240.
240.
240.
240doesnotlikerecipient.
Remotehostsaid:550-VerificationfailedforJohn.
Doe@YourDomain.
com550-Called:250.
250.
250.
250550-Sent:RCPTTO:John.
Doe@YourDomain.
com550-Response:554:Serviceunavailable;Clienthost[server11.
virgohosting.
net]blockedusingBarracudaReputation;http://recipientdomain.
barracudacentral.
com/q.
cgiip=230.
230.
230.
230550SenderverifyfailedGivingupon240.
240.
240.
240Thefollowingaddresseshadpermanentdeliveryerrors"Thefollowingaddresseshadpermanentdeliveryerrors"/"Thefollowingaddresshadpermanentdeliveryerrors":Eitherofthesesentencesareusuallyfollowedbyoneormoreemailaddress(es).
Theerrormessageiseffectivelysayingthattheemailaddresseslisteddonotexist,ornolongerexist(ifyouusedtobeabletoemailtothemsuccessfully).
Youneedtogetthesendertoverballyverifywiththerecipientwhathis/hernewemailaddressis.
Mailboxisinactive(ThehostingISPishavingproblems)Atypicalerrormessagemightgolikethis:"Amessagethatyousentcouldnotbedeliveredtooneormoreofitsrecipients.
Thisisapermanenterror.
Thefollowingaddress(es)failed:XXXXXXMailboxisinactive".
ThiserrorisalmostalwaysaproblematthehostingISPwhichhoststhePOPbox(es)oftherecipient'semailaddressordomain.
Youneedtoinformtherecipientthatthereisaproblemwiththeirhostingcompany.
So,forexample,ifyouaresendinganemailtoJohn.
Doe@clara.
netandyougetthe"Mailboxisinactive"error,thenyouneedtotellJohnDoethathishostingISP,ClaraNET,arehavingproblemswithincomingemailsandthatheshouldtalktothem.
oooooooOOOOOOOooooooo
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