Can't add new email account

I have a self hosted version 5.1.x of Zammad. The plan is to change the email accounts to Microsoft 365, which worked perfect. As mentioned in the documentation, I want now to add a simple IMAP/SMTP account of our Domain-Hoster for the email notification.
I created already multiple accounts (alway subdomain from our domain… e.g., and they seem to work. Every test online and with an email client was successful.
If I try to add one of this accounts to Zammad, the configuration over _autodiscover does not work. If I try to enter the data manually, It also doesn’t work.
I tried an old adress with a different domain and no sub-domain (same provider) and it worked in seconds. Sadly, I can’t use this address.
Is there a way for me to find out what’s causing the isse (any log or test I can do)?
Did someone else already face this issue?

What is the error message belonging to “does not work”?

Hello MrGeneration,

after I click on new and enter the data (email, password), I get the error message: Die Servereinstellungen konnten nicht automatisch erkannt werden. Bitte konfigurieren Sie diese manuell.

Which is already strange, because I tried with some other accounts at the same isp (different domains) and they work immediately. Maybe there is an issue because I use a subdomain? instead of

I enter the imap data manually, next, I end up with the smtp configuration. I also enter the correct data (tried with some email clients, works) but after a while of “verify send and receive” I get the error: Versand und Empfang von E-Mails konnte nicht verifiziert werden. Bitte prüfen Sie ihre Einstellungen.

Nothing more.

If you want, I can hand over the complete account information for testing. It is an account we created for our ticket system, and is not used for anything else. We did this, because we want to change from smtp to microsoft 365.


I can try the credentials if you want to. You can send them via PM if you want to.
I can’t think of a reason why one method works and the other doesn’t.

Automatic detection failing can be possible depending on the setup. Zammad has limitted magic finding capatility.