[Dovecot] IMAP to Maildir Migration preserving UIDs?

[Gedalya]

On 01/26/2012 11:02 AM, Ed W wrote:
> Hi
>
>> Sounds very cool. I already have dovecot set up as a proxy, working, 
>> and it should allow me to forcefully disconnect users and lock them 
>> out while they are being migrated and then once they are done they'll 
>> be served locally rather than proxied. My main problem is that most 
>> connections are simply coming directly to the old server, using the 
>> deprecated hostname. I need all clients to use the right hostnames, 
>> or clog up this new server with redirectors and proxies for all the 
>> junk done on the old server.. bummer.
>
> Why not put the old server IP to redirect to the new machine, then 
> give the old machine some new temp IP in order to proxy back to it?  
> That way you can do the proxying on the dovecot machine, which as you 
> already established is working ok?
>
> Good luck
>
> Ed W

Yeap, taht's what I'm doing to do, except that I would have to proxy 
more than just IMAP and POP - it's a one-does-it-all kind of machine 
accepting mail delivered from the outside, relaying outgoing mail, does 
webmail, does all this things very poorly... I have the choice of 
forcing all users to change to the new, dedicated servers doing these 
things, or reimplementing / porxying all of this on my new dovecot 
server which I so desperately want to keep neat and tidy...