Authentication Failed!


  • Used Zammad version: 5.2.x
  • Used Zammad installation type: package
  • Operating system: Ubuntu 20.04
  • Browser + version: Chrome

Expected behavior:

Add a new mail succesfully.

Actual behavior:

More exactly, this error appear today, and it was unexpected, just start the below error on all the mails that I was trying to send:

Next to this, I was reading a lot of forums with this error and this was a old error on 2020.
I just tried to delete that email on zammad and tried to configure again but now I receive the below error:

I already verified the password, the email, I change the password and tried again but everything works bad :frowning:

It also appear with gmail accounts.

Steps to reproduce the behavior:

Just try to add a new email.


You can try it without the SSL.

Basically, Zammad is receiving this error message from Your server.
For some reason, Zammad can not connect to your mail server with these credentials.

I would try to connect the mail account to a Mail client, and investigate why the mail server doesn’t allow the connection.


Hi @Bozo0511, I really apreciate your dedication for this case, but it is already solved… How you say, my mail server is the problem, after talk with support from my mail server, I recived that someone try to use my account and for that reason they changed the autentication credencials.

1 Like

Please read this article: Basic Authentication and Exchange Online – September 2021 Update - Microsoft Community Hub

there you can temporary re-enable legacy authentication for IMAP and SMTP

for a permanent solution, you will need to change the Email integration to 365 Integration using Oauth 2.0 instead of legacy auth

please note, if your 365 does not allow user consent for enterprise application (365) you will need to upgrade to Zammad 5.2.3 to support admin consent

Wrong topic mate. The affected maibox is not a microsoft 365 mailbox.

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