[Dovecot] Migrating from CourierMail to Dovecot

[Robert Moskowitz]

On 03/07/2013 08:19 AM, Robert Moskowitz wrote:
> My current mail server is a Fedora12 system running 
> postfix/mysql/couriermail/squirrelmail mix.
>
> My new server is a Centos6 running 
> postfix/mysql/postfixadmin/dovecot/roundcube mix.
>
> I have 4 virtual domains and about 20 users; not a big setup by any 
> measure.
>
> Both servers have the same host name, but are currently on separate 
> subnets.  My current plan is to stop services on the old server, 
> switch them on subnets, rename the old server, and let 'slow users' 
> drain the old server over a couple of days.
>
> Then I got to thinking, could I migrate the 
> /home/vmail/domain/user/new folders from the old to new server? Not 
> too many rsync commands to run to pull it off, but would that work? Is 
> there something dovecot needs to do, and not just drop the files into 
> the .../new folder?  Or is there some utility to run to properly place 
> the mail files?
>
> The file names are similar.  Courier file names look like:
>
> 1362661301.Vfd01I2422e6M121970.klovia.htt-consult.com,S=17381
>
> Whereas dovecot adds a ",W=nnn" string to the file name.  I am 
> assuming the content is otherwise the same.
>
> I would like to test out the migration, and then pull it off over a 
> sunday.  Due to meetings and holidays, this won't happen until early 
> April, so I have time to work out the details.
>
> All guidance and pointers are greatly appreciated.

Forgot to include that all users are only popping their mail.  Some use 
of squirrelmail to check mail while on the road, so I don't have to 
migrate any imap directories.  This will change with the move, I myself, 
will move to imap after popping mail for ~20 years...