[Dovecot] Maildir migration and uids

[David Jonas]

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?