username mapping for imap/pop

[bidwell]

I need to map from username to login name where I wish to map from just
username to username at domain.org for gmail and windomain\username for an
exchange server.  Is there a way for me to build in hooks to change the
username before connecting.  I can to that in my mailauth.pm module but
don't know how to return the updated username.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,246296,246296#msg-246296