Hi Jeff, I wrote a plugin that I posted to this list a while back that will authenticate to the local IMAP server, so if you already have IMAP or POP3 setup on your server with whatever backend authentication mechanisms you might need (vpopmail, etc), you don't have to worry about a second authentication method or different way of accessing them.
The one caveat being that your implementation only supports cleartext methods like auth-plain (and auth-login if you added it). Because you need the cleartext password to perform the backend authentication, there is no way to support auth-cram-md5. That may be an acceptable limitation for some sites, but doesn't lend itself to a generalized solution.
John
