The current version only needs a Maildir which you can
do with most MTA's (at least that is what I understand
from the code) so I am not sure why there would be a
dependency on Qmail.
Personally I prefer Maildir + sweeper to something that tries
to do direct inserts to the db (since I am more confident
that mail won't be unaccountably dropped).
Also, I think the silent deletion and failure to track bounces
was fixed by Mat Kovach.
And finally, it does in fact work (with the caveats about not being smart about attachments, quoted text, etc). For example dotlrn.org can accept incoming email to the forums. I would not be surprised though if there were bugs in the oracle version that have not been fixed.
see bug 1843 for the tracking bug.
