I found a problem during testing. Version postfix 3.9.0. When using
dovecot sasl for verification, if dovecot dies or the network connecting to
dovecot fails, smtpd will not be able to return 220. Mail cannot be received. I
used net socket to connect to dovecot. Is it possible to judge the con
Eventually I will remove sasl from port 25. But since port 25 can use sasl
authentication, the reliability of the service should be ensured. Once dovecot
sasl terminates unexpectedly, it will cause a complete strike of smtpd on port
25. Any connection will not be responded. I think the high coup
