[Dovecot] UIDL and message migration

[Timo Sirainen]

On Tue, 2011-06-21 at 12:17 +0100, Hugo Monteiro wrote:
> Hello,
> 
> I'm in the process of migrating accounts between two dovecot servers. An 
> old server running ancient 1.0.15 and a new server running 1.2.15.
> Account migration is going to be gradual and so i would like to use 
> imapsync to move messages and subscriptions from one server to the 
> other. The only problem so far is with POP users. After doing an account 
> migration with imapsync, and although both servers share the same 
> pop3_uidl_format = %08Xu%08Xv, the client downloads every message that 
> was already on the server.

%u means IMAP UID. imapsync can't preserve those. Use either rsync on
the filesystem directly or v2.0's dsync.