I no longer have access to an MS Exchange server. Also, this project should have been written in Perl from the start. If a GUI alternative is acceptible to you, then you should use Ximian Connector, which is now open source.
Personally, I don't think I'd want a GUI mail client, because I'd like to be able to read mail remotely, and potentially over a slow uplink.
If you offer me a user account on an Exchange 5 or 2000 server, I'll rewrite this in Perl. I suspect that it'll only take me a few hours to get most of the functionality working, and I expect that I'd be in a better position to make attachment support work than I am right now, with this code.
Release 9 is out, now with attachment support. Fixes some bugs from 8, but maybe not as well tested.