[Dovecot] POP - preventing re-download with server move

[Robert Schetterer]

Am 24.11.2011 15:46, schrieb Trutwin, Joshua:
> Hi,
> 
> Curious if anyone has any good suggestions to handle this.
> 
> I try to get my hosting users to use IMAP but most use Outhouse and
> the IMAP support is somewhat annoying for many so I typically have
> them change their settings when using POP to leave copies on the
> server.  That way when they get the inevitable virus or wanna use
> webmail they have a backup copy and webmail sees their saved mail.
> 
> So now I have to move my sites to a new server and I'm trying to
> avoid having all these messages re-downloaded by POP clients.  Some
> of the sites I've moved with low email usage have just dealt with the
> re-download and cleaned up afterwards.  I have a few other accounts
> though that I'm more concerned about that have massive amounts of
> stored email.
> 
> The mail is stored in Maildirs - a sample file: 1280409166.23580.foo:2,S
> 
> If I move this to server "bar" would renaming the file to
> 1280409166.23580.bar:2,S prevent this somehow?
> 
> Old server uses qmail-pop, new server uses dovecot 2.0.
> 
> Thanks for any tips,
> 
> Josh

perhaps
you can do it i.e like this
use imapsync with diff between the two servers
then block pop3 with firewall for public
on the old one, run a last sync session,
change dns and/or ip etc , users use new server
i think this is the most secured way, i did it like this

the problem
by redownload may stay cause the pop3 clients
have their own list of mail downloaded etc build by i.e with some one hashes
i.e.
http://kb.mozillazine.org/Popstate.dat

and i dont know some way to press them to download anything
-- 
Best Regards

MfG Robert Schetterer

Germany/Munich/Bavaria