I have a new mail server configured as described in this howto: http://howtoforge.com/virtual-users-domains-postfix-courier-mysql-squirrelmail-ubuntu-9.10
I also have an ancient mail server configured very similarly (using the same HOWTO, just for Fedora Core 6, if I recall correctly).
Earlier today I had to switch from the old server to the new one, and the old one is no longer online. However, after I had migrated everything and switched it all over, I discovered a bunch of undelivered mail in the queue. It got delivered to the local mailboxes on the old server, so now there are a bunch of messages on it that I'd like to move to the new server. The new server has already received new messages, so I need to merge the files together somehow.
For each user with an email of email@example.com, there are files like this on both servers:
/home/vmail/customer.com/username/maildirsize /home/vmail/customer.com/username/courierpop3dsizelist /home/vmail/customer.com/username/new/1271481177.Vca01I6006bM580357.mailhost.mydomain.com
Can I simply copy the hundreds of files in the various new directories on the old server to the corresponding new directories on the new server? Will the maildirsize and courierpop3dsizelist files get updated automatically, or do I need to do something to update them?