Hello, I need to move around 800 email accounts to our new cPanel server with Courier daemon. Problem is, the old pop3/imap username format is not in form email@example.com. Changing usernames and notifying computer illiterate users would be a time and nerve intensive work. So, I've come to an idea to simply somehow map old usernames to email accounts. Example map file: customuser123 firstname.lastname@example.org ... Only thing needed now is to somehow tell Courier, which old username maps to which new and authenticate against new. I see a custom compiled perl binary called /usr/local/cpanel/bin/courier-auth, which does the work of authenticating, it's called by authdaemond. Is it possible to make a wrapper around this compiled binary, to pass the rewritten username to it? Is the source available? I could then add the functionality directly. Thanks for any tips or info!