I normally connect the mailboxes to POP3 and sync them so I have a local copy.
Then after connecting the new mailbox to the computer you can push the mail back onto the server.
It's a pain but that's my process normally
I normally connect the mailboxes to POP3 and sync them so I have a local copy.
Then after connecting the new mailbox to the computer you can push the mail back onto the server.
It's a pain but that's my process normally