Mail delivery fails: Error 554: host refused to talk to me

Symptoms

• Mail delivery to particular domains fails with the following error message in /var/log/maillog:

  CONFIG_TEXT: 0572C2801E1: uid=30 from=john.doe@example.com
  0572C2801E1: message-id=6AD1BED0ECFB2E4FA52CC9B923AE4ED6A50F7157@example.com
  0572C2801E1: from=john.doe@example.com, size=3826, nrcpt=1 (queue active)
  0572C2801E1: host mx.example.net refused to talk to me: 554 IP=IP_ADDRESS - A problem occurred. (Ask your postmaster for help or to contact info@mx.example.net to clarify.) (BL)

• When manually connecting to the remote server from the error message (In this example, mx.example.net) using the telnet utility, connection fails:

  # telnet mx.example.net 25
  Trying mx.example.net....
  Connected to mx.example.net.
  Escape character is '^]'.
  554 IP=IP_ADDRESS - A problem occurred. (Ask your postmaster for help or to contact info@mx.example.net to clarify.) (BL)
  Connection closed by foreign host.

Cause

Error code 554 means IP-Blocking: A remote mail server is not currently accepting emails from a server IP address. This IP blocking may be due to a previously observed unusual volume of emails at the IP address concerned.

Resolution

Contact administrator of a remote mail server.

For more information about a blacklisted mail server, see this KB article:

• Plesk Mail Server is blacklisted. What to do?

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