mailinglists@belfin.ch put forth on 2/10/2010 3:01 AM:
And the other question is, is there any mail user agent that would support server-side full text indexing and not create own indexes?
Thunderbird. Maybe all MUAs? Usually with smartly designed MUAs body searches are left to the IMAP server to perform. On standard TB, in the absence of about:config hacks, one cannot run a body search on an IMAP folder unless you check the "Run search on server" box. Anything else is a header search, and headers are already indexed by TB for pretty much everything. TB doesn't index IMAP message bodies, _unless_ you have IMAP folders synchronized locally and are running in offline mode. In the offline case your search will utilize a local index of message bodies.
-- Stan