I having a bit of puzzle recently. I have ispconfig runs as the gateway as well. It has two eth cards. The goal is having functionality that allow postfix to send emails form the local IP. I'm having some scripts on the other local workstations that there sending email by ssmtp command, but stop doing. Maybe because mail server has most of the protection such us SPF, DKIM,DMARC. Is any way around it?
See the read before posting on "I can't send/receive mail" https://www.howtoforge.com/community/threads/please-read-before-posting.58408/
To clarify, the local workstations are sending mail to mailboxes which your mail server hosts? Or they are trying to relay mail through your mail server to external domains?
The first one. I just realized that ssmtp command do not support TLSv1 and above. Another words main.cf should have only: Code: smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 smtpd_tls_protocols = !SSLv2,!SSLv3 smtp_tls_protocols = !SSLv2,!SSLv3 problem solved
