I've heard of similiar issues. However the developers at DBMail seem to have mafe it around the issue. I could chat with them about it.
In the interest of curiousity, is the message store to the filesystem in just a few methods? or is it burried in the entire system? If it wouldn't be too hard I might just want to play around with it.
I'll be digging into the code next week to get myself familiar, so will probably will just find it, but thought I'd ask
Thanks,
Kevin