Trouble Authenticating to Mail Server - Logs? Suggestions?


We have been unable to get Nextcloud to send mail to external users. We know this is likely an authentication/relay issue with our mail server, however we have been unable to fine an authentication method that works. If we turn off authentication we are able to send mail to internal users without a problem.

Where can we find logs in Nextcloud to help us determine what the issue might be?

Are there any suggestions on what the mail settings should be for connecting to an Exchange 2013 server for an authenticating user?

Nothing? Nobody can point me to a nextcloud log that might give me a better description of the issue?


For email config please see

So obviously we’ve read this time after time. However no option we select are we able to send mail when it requires authentication. It just keeps saying authentication failed. Where/how do you specify the domain for authentication with an Exchange server?

One thing that comes up no where in the documentation is that php-bcmath is required for NTLM. Once we installed that we were able to authenticate to the domain and send mail.