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Error code wiki · 3 codes

Telekom SMTP error codes

Deutsche Telekom runs the t-online.de mailboxes of its German internet and freemail customers, and its own postmaster team handles the mail sent to them.

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Permanent failures (5xx)

2 codes

The receiving server refused the message for good. Your server will not try again, and the message comes back to you as a bounce.

  1. 550 5.7.0Message classified as spam or virus.The Telekom spam filter classified your message as spam or as carrying a virus and rejected it after the DATA phase. False positives can be reported.Permanent
  2. 554IP address blocked.Telekom is not accepting mail from your IP address at all, usually after unusual mail volume from it. The reply names the contact to ask for review.Permanent

Temporary failures (4xx)

1 code

The receiving server cannot take the message now. Your server keeps it and retries, and only bounces it if the retries run out.

  1. 421Too many parallel connections.Your server opened too many simultaneous connections to the t-online.de mail servers, so the extra ones were refused for now and the mail is delayed.Temporary

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