New in mailsync-4.2.2:

 * password can be set in stores/channel

New in mailsync-4.2.1:

 * recursive copying should work now

 * comments in config files

 * minor bugfixes and cleanups

New in mailsync-4:

 * If the same new message is in both stores, it's left alone.
(mailsync-3 would copy it in both directions, wasting bandwidth and
creating duplicates).

 * Now makes a single pass through each mailbox instead of two.  This
reduces network bandwidth (though probably only a little, not by 50%).

 * Can handle either or both stores being empty.

 * List mode ("mailsync store") and diff mode ("mailsync store
channel") fixed.  Diff mode no longer removes duplicates.

 * The per-mailbox summary lines ("foo: 1 deleted, 30 remain") now
appear before the copying & deleting are done.  So if you see 
"foo: 4384 copied local->remote" you can hit ^C sooner.

 * Now mailsync is a C++ program.  Reduced from 2000 lines of code to
1200.  Data formats (.mailsync and msinfo) remain unchanged.  Fewer
memory leaks and less opportunity for buffer overflows (though I don't
know of any in mailsync-3).

