Cyrus POP3 and OS X Server

[Joe Topjian]

Hello -

I realize that this question is based on OS X Server and not a true
Cyrus installation, but I thought I would ask anyway.

I'm having a problem where I would like people to authenticate by
their full email address (such as joe at server1.local). In the OSX
Directory Service, I have given each user two usernames:
local_server1_joe and joe at server1.local. Mail is delivered to the
mailbox and user local_server1_joe.

Using Cyrus IMAP, I'm able to authenticate with joe at server1.local and
view the mailbox local_server1_joe.

However, with POP, Cyrus will authenticate correctly, but create a new
mailbox on the fly of joe at server1^local.

Is there anything I can do to fix this? Or is this more of an internal
OS X thing that is broke?

Thank you
-Joe