Following an outage, I've ended up with 2 mailboxes for each of my users, on separate machines. I've shut the interim machine down now, and put the mailboxes on the real server in
/srv/scratch/$username/Maildir/..., and need to integrate the messages from them, ideally preserving read/seen state, into the users' canonical mailboxes,
/srv/mail/$username/Maildir/.... I have no preference for whether this is as a sub-folder, or in their main inbox, however I am confident none of the temporary mailboxes contain sub-folders themselves. (If they do, more fool the users, who were explicitly told not to do this on the temporary accounts!)
Is there a good way to do this which minimises risk of loss of mail, and means their clients will automatically pick up the new folder/messages (whichever it needs to be) when they reconnect? Alternatively, what do I need to do to tell Dovecot about the new messages after dumping them into the Maildirs?
Both servers were built using Exim4 for delivery and Dovecot for IMAP.