I just finished following this tutorial on Digital Ocean for configuring a Dovecot, MySQL, and Postfix email server. I did not follow it to the end. (I didn't install Spam Assassin.) I also used a self-generated SSL temporarily. Other than that, I followed the tutorial to the letter. At every point where I was told to do a test command, I did so and the results were what the author said they should be.
The problem is that using an email client (like Thunderbird) I cannot login to the server. However, using Telnet I can connect to SMTP on ports 587 and 25. I can also connect to IMAP on port 993. (25, 587, and 993 are the ONLY ports I have forwarded from my external IP.)
I have checked the data in the MySQL DB. My user exists with my desired password.
How can I troubleshoot the issue here? Is there a way to test login credentials using telnet?
Authentication is the issue. I've initiated the connection with
openssl s_client -connect mail.example.com:587 -starttls smtp (Thanks 84104). My exchange then looks like this…
ehlo example.com 250-hostname.example.com 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-AUTH PLAIN LOGIN 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN AUTH LOGIN 334 VXNlcm5hbWU6 MyBase64EncodedUsername 334 UGFzc3dvcmQ6 MyBase64EncodedPassword 535 5.7.8 Error: authentication failed: Connection lost to authentication server
Is there a debugging route I can take to find the problem? Is this simply authentication or a connection issue?