Re: force postifx to look up again for mail exchangers
> The Postfix SMTP client **always** looks up the current list of
> MX hosts and IP addresses. If it gets the wrong information, you
> need to update your system configuration.
Pedro David Marco:
> Thanks Wietse...
> does this also happen with connections saved in scache?
By default, a connection is not reused after 300 seconds
(smtp_connection_reuse_time_limit = 300s), or after it hasn't been
reused for 2 seconds..
SMTP connections are cached by name and by IP address. When the
IP address becomes invalid, all connections with that IP address
break. When the Postfix SMTP client wants to reuse a connection it
sends an RSET command, which fails with a broken connection, after
which the Postfix SMTP client makes a new connection.