Pre-sync'ed folders?

[Dave Abrahams]

Suppose I have already synced two folders, but I've thrown out all the
information stored in ~/.offlineimap.  When I sync again, is there
anything to prevent offlineimap from copying all the messages in both
directions, thus ending up with duplicates in each folder?  As far as I
can tell, offlineimap (almost) never looks at the Message-ID header, so
I imagine it would have no reason to identify copies of the same message
that already exist on both sides... right?

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com