Hi,
centos 7.4
Plesk 17.5 latest Updates
mailman
greylisting
the maillinglists have worked without problems but now Mailman doesnt send Emails.
In Serverwide whitelist i have
127.0.0.1 / 32
::1 / 128
In /var/log/smtp-failure i see
delivery to
[email protected] failed with code 451: 4.7.1...