Don Cohen via Postfix-users: > $ telnet 96.103.145.163 25 > Trying 96.103.145.163... > Connected to 96.103.145.163. > Escape character is '^]'. > 554 resimta-a2p-651038.sys.comcast.net resimta-a2p-651038.sys.comcast.net > 129.80.158.55 > found on one or more DNSBLs, see > https://postmaster.comcast.net/smtp-error-codes.php#BL000001
I invite you to look up the documentation for smtp_skip_5xx_greeting at https://www.postfix.org/postconf.5.html#smtp_skip_5xx_greeting Additional context from https://datatracker.ietf.org/doc/html/rfc2821#section-3.1 The SMTP protocol allows a server to formally reject a transaction while still allowing the initial connection as follows: a 554 response MAY be given in the initial connection opening message instead of the 220. And... Since an attempt to make an SMTP connection to such a system is probably in error, a server returning a 554 response on connection opening SHOULD provide enough information in the reply text to facilitate debugging of the sending system. Following RFC 5321, Postfix assumes that the connection is made in error (it does not parse the free text portion of server replies) and tries another server. If you disagree, then you can change the Postfix configuration. Wietse _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
