Hi Tim,
Our product uses the qmail mailer and stores incoming messages in "Maildir" format, which is a great deal more reliable than the traditional mbox format. Unfortunately, this means that standard IMAP servers don't work out of the box with our software.
We're planning to have IMAP support in the next version of the product. In the meantime, if you know of any IMAP servers that can deal with the Maildir format, they should work with the e-smith server.
Thanks for your feedback and supportive comments!