dovecot - Dec 2011 - Maildir migration and uids

I'm in the process of migrating a large number of maildirs to a 3rd
party dovecot server (from a dovecot server). Tests have shown that
using imap to sync the accounts doesn't preserve the uidl for pop3 access.

My current attempt is to convert the maildir to mbox and add an X-UIDL
header in the process. Run a second dovecot that serves the converted
mbox. But dovecot's docs say, "None of these headers are sent to
IMAP/POP3 clients when they read the mail".

Is there any way to sync these maildirs to the new server and maintain
the uids?

The real goal is keep customers email clients happy when they are
pointed at the new server. Am I just wishing?

On 22.12.2011, at 3.52, David Jonas wrote:
> I'm in the process of migrating a large number of maildirs to a 3rd
> party dovecot server (from a dovecot server). Tests have shown that
> using imap to sync the accounts doesn't preserve the uidl for pop3
access.
> 
> My current attempt is to convert the maildir to mbox and add an X-UIDL
> header in the process. Run a second dovecot that serves the converted
> mbox. But dovecot's docs say, "None of these headers are sent to
> IMAP/POP3 clients when they read the mail".
That's rather complex.
> Is there any way to sync these maildirs to the new server and maintain
> the uids?
What Dovecot versions? dsync could do this easily. You could simply install the
dsync binary even if you're using Dovecot v1.x.

You could also log in with POP3 and get the UIDL list and write a script to add
them to dovecot-uidlist.