[Dovecot] Help! OT: Blackberry IMAP client suggestions/experience needed

[Ed W]

>  
> You might consider how to direct your needy users to a mail server 
> instance that has Maildir.  If you are afraid, or its difficult to 
> wedge this into your current setup, you could have a completely 
> different mail server host their mail, and you could use a MX server 
> and/or a perdition IMAP proxy to redirect them invisibly to this other 
> server once you've moved or copied their data.  I wanted to avoid this 
> path and get the migration over with, but I caved in and started going 
> after the power users and the low hanging fruit.  I'm very glad I did, 
> because now I can migrate users one at a time and deal with any 
> problems that arise on my schedule, and when I am prepared in the 
> future, I can throw some switches and move the remaining users over 
> that are unrealistic to handhold. 


Dovecot does fairly decent proxying also.  I did my migration from 
Courier in the same way - configure the new server to take all 
connections, then proxy them back to the old mail server if they were 
still on that server.  Then wrote a script to move them over one by one 
and update the DB.  Worked very nicely with minimum downtime and you can 
stop the migration at any point if you find problems (eg mine happened 
over a month or two...)

I needed to get dovecot to change it's CAPABILITY response to match the 
common abilities between both servers, but apart from that nothing 
special needed for proxying...

Ed W