What, do you think that MB-IMAP has a GUI ?
It is an IMAP server, running as a daemon, there is nothing to show!
I could make some screenshots of an IMAP session done by telnetting to the port 143.
And here is a screenshot of the old perl management console:

Note that the data you see here is just fake. The interface looks a little "n*vellish" because it is inspired by N*vells rc*nsole.