[Dovecot] looking for IMAP testing tool

[Phil Howard]

I'm looking for an IMAP testing tool, suitable to use with Dovecot IMAP.  It
needs to support TLS, STARTTLS, and login/authentication.  It needs to be
able run from command line, shell scripts, and even do so under cron jobs
(e.g. a way to supply the password to use w/o a terminal prompt).  Typical
interactive mail clients just don't cut it (even the text mode ones).  One
reason is I need to do the tests on a number of machines, under a number of
user and domain names, and with a variety of parameters or destinations.
This is for a suite of regression tests I am putting together intended to
verify that configuration changes do not break things (or unbreak things
that are supposed to not work).

Anyone ever heard of such a tool?  Open source would be preferred (better
yet, my favorite programming languages: C, Pike, Python).