Hi everyone,

Other MUAs (mutt, courier-imap) store certain information about the
status of messages in the filename. Basically they add an S to the end
of the message if it has been seen, R if it has been replied,
etc.

This is all decribed at:
http://cr.yp.to/proto/maildir.html

Gnus doesn't use these flags. So if you use gnus to read mails in a
maildir and then access the same mail in mutt, the mails will appear
to be unread. If you had read them in mutt first mutt will add the S
(seen) flag, but gnus ignores it and the message would still appear to
be unread.

To fix this I've made a little perl script (~= 100 lines) for myself
that syncs the two. It looks at gnus's marks and adds flags to the
messages, then it looks at the messages' flags and adds gnus marks.

The ideal solution would be to have gnus add the marks directly. I
don't enough lisp to pull this off.