I spent some time trying to get POP3 authentication to work with no luck. Finally I made the following change to the open call in auth/pop3/lib.php:
$connection = imap_open($host, $username, $password, OP_HALFOPEN);
was replaced with:
$connection = imap_open($host, $username, $password);
This change seemed to solve all my problems. According to the PHP documentation OP_HALFOPEN is for IMAP and NNTP servers. There is no mention of POP3. And it appeared on my system at least (and with several different servers) that including the OP_HALFOPEN parameter in this function call caused it to always fail when connecting to POP3 servers. The purpose of the parameter is to make it connect to a mail account only rather than connecting and opening a mailbox. Has anyone else had any luck with using POP3 authentication with the existing code?
While I was in there, I added a parameter for configuring the mailbox to connect to (since removing the OP_HALFOPEN makes it require one) rather than hardcoding INBOX. I also modified a few of the strings that I found confusing. My modified files are attatched here. File locations are as follows:
/auth/pop3/lib.php
/auth/pop3/config.html
/lang/en/auth.php