[Dovecot] Seen flag getting lost

[Edgar Fuß]

> That shouldn't happen because of Dovecot's indexes.
Hm, also if the indexes are local? Fine.

> Then the 'S' flag is added to the current Maildir filename without
> losing any other changes.
And this is supposed to work even over NFS? Great.

So, what can I do to track down the problem as, according to what I read from your answer, it's probably a Dovecot bug?