SMTP problem "OK The Microsoft Exhange IMAP4 service is ready

Infos:

  • Used Zammad version: 5.2.x
  • Used Zammad installation type: package
  • Operating system: Ubuntu 20.04.5
  • Browser + version:

Expected behavior:

  • I can´t change the notification mailadress to a mailadress on our exchange server.

Actual behavior:

  • I get every time the message "OK The Microsoft Exchange IMAP4 service is ready.

Steps to reproduce the behavior:

  • Our exchange server allows sending mails without authentication. I have tested it with the ports 143, 25, 587 and 993.

You really can’t wrap your head around this message within SMTP context?

OK The Microsoft Exhange IMAP4 service is ready

How about you use actual SMTP ports for sending emails instead of IMAP ports?
Port 993 as an example, by RFC, is not an SMTP port.
Nobody can help you with this topic if your exchange uses different ports for SMTP.