Vor einer Weile war in der MailEnable KnowledgeBase eine kompakte Tabelle mit SMTP Statuscodes zu finden. Die Tabelle wurde Anfang 2010 durch einen umfangreichen und sehr detailierten Troubleshooting-Guide ersetzt: ME020032 – INF: SMTP Connector Inbound Response Codes.

Hier die ursprüngliche Tabelle zur einfachen Übersicht:

SMTP Status Codes

Status 2xx „Success“

200nonstandard success response (see rfc876)
211System status, or system help reply
214Help message
220<domain> Service ready
221<domain> Service closing transmission channel
250Requested mail action okay, completed
251User not local; will forward to <forward-path>

Status 3xx „Wait for“

354 Start mail input; end with <CRLF>.<CRLF>

Status 4xx „Temporary Error“

421Service not available, closing transmission channel
422The recipient has exceeded their mailbox limit
431Not enough disk space on the delivery server; may be reported as out-of-memory error
432the Administrator has frozen the queue
441Intermittent network connection, the server has not yet responded
442The server started to deliver the message but then the connection was broken
446Too many hops. Most likely, the message is looping
447Timeout occurred, check server connection
449A DNS problem occurred; check your smart host setting on the SMTP connector
450Requested mail action not taken: mailbox unavailable
451Requested action aborted: local error in processing
452Requested action not taken: insufficient system storage
465Your server does not have the correct language code page installed

Status 5xx „Permanent Error“

500Syntax error, command unrecognized
501Syntax error in parameters or arguments
502Command not implemented
503Bad sequence of commands
504Command parameter not implemented
510Bad email address
511Mailbox not found
513Relaying denied or Address type incorrect
514Two objects have the same address
515Destination mailbox address invalid
516Mailbox has been moved
517Command violates RFC 821; most likely missing < > around email addresses
521Server does not accept incoming mail
522Recipient has exceeded their mailbox limit
523Recipient cannot receive messages this big
524Most likely, a distribution list or group is trying to send an email
530Access denied
531Mail system full; most likely Exchange database full
532System not accepting network messages
533Remote server has insufficient disk space to hold email
534Message too big
535Multiple Virtual Servers are using the same IP address and port; see MS KB321721 „Sharing SMTP“
540There is no DNS server that can resolve this email address
541No answer from host
542Bad connection
543Routing server failure, no route available
544Cannot find the next hop, check the Routing Group Connector
546Tricky looping problem, a contact has the same email address as an Active Directory user
547Delivery time-out
548Bad recipient policy
550Requested action not taken: mailbox unavailable
551User not local; please try
552Requested mail action aborted: exceeded storage allocation
553Requested action not taken: mailbox name not allowed, possibly more recipients than allowed
554Transaction failed
555Wrong protocol version
563More than X attachments
571Permission problem, most likely anonymous user is trying to send mail to distribution list
572Distribution list cannot expand
573External IP address of ISA server does not match SMTP publishing policy
574Extra security features not supported, check delivery server settings
575Cryptographic failure, try a plain message with encryption
576Certificate problem, encryption level maybe too high
577Message integrity problem

SMTP 550

Der Statuscode 550 (oder 5.5.0) scheint ein Spezialfall mit unterschiedlicher Bedeutung zu sein. Im besten Fall lässt sich über die mitgelieferte Text-Statusmeldung mehr herausfinden, zB. deutet „550 this address is not allowed“ auf einen unauthorisierten Benutzer hin (SMTP-Auth im Email Client vergessen?). Die textuelle Fehlermeldung ist in verschiedenen Email-Serverprodukten meist unterschiedlich formuliert. So bedeuten „550 queue expired“ unter Microsoft Exchange als auch „550 message expired“ unter MailEnable, dass die Nachricht nicht innerhalb der vorgegebenen Zeit zugestellt werden konnte.

Quellen und zusätzliche Informationen: