[Dovecot] Bad creation timestamp of migrated mails (maildir format)?

[Lukas Weiß]

On Fri, 04 Nov 2011 22:33:09 +0200, Timo Sirainen wrote: 

> On
Tue, 2011-11-01 at 09:38 +0100, Lukas Weiß wrote:
>>>> and sql storage
is difficult to backup. Ive done that, by setting up dovecot with
maildir format and copy mails from old dbmail to new dovecot imap server
with my mail client (thunderbird).
>> 
>>> Thunderbird probably changes
the INTERNALDATE of
>> the messages. Copy the mails some other way, like
offlineimap or maybe some other IMAP client. What is INTERNALDATE? The
modification timestamp is correct ("ls -l"), and the "Date: ... " line,
too.
> Maildir file's mtime is the INTERNALDATE, yes. Maybe the the
problem isn't then any timestamps, but that the messages were copied in
reverse order (newest message first), so their IMAP UIDs are
reversed.

Possible. How do i avoid this? What is the preffered way to
migrate mails from one to another imap server? Offlineimap? Can i do a
save sync with that, even if my dovecot has newer mails now?