I recently transferred one of my domains to a different registrar. I updated the name servers to point to the right location, and then went through the process of recreating all of the mailboxes, then updating the passwords in exchange's POP3 Connector.
Easy enough, I thought. However, exchange is no longer downloading mail from the mailboxes. Upon checking the server logs, I notice that the error is pretty obvious:
ERR: AUTHENTICATION FAILED
I can logon through webmail perfectly fine so I know for a fact the passwords work, but I reset them just for good measure and I reset them to something extremely hard to screw up: abc123.
I then figured I'd telnet into the mailbox to see if I can authenticate that way, but no dice. Same error.
But here's the really weird thing: I can set any of the accounts up in a pop3 client (I use thunderbird) and it works perfectly fine.
I feel like I'm missing something extremely obvious here. Can anyone explain what's happening here or, better yet, suggest what I can do to resolve the issue? I'm all out of options.