I’ve migrated from another email server to Mailcow. Long story short, I managed to migrate the mailboxes with these steps:
Created the @tempdomain.com domain on Mailcow and set it up until it could successfully send and receive external emails.
Connected the identity provider to the OpenLDAP I had set up.
Imported all the previous user mailboxes into the Mailcow server under @tempdomain.com. I also ran a sync job between @domain.com and @tempdomain.com using the settings I configured in Mailcow.
Now, my main confusion is: how do I switch the mailboxes from @tempdomain.com to @domain.com once the migration and sync job are done, before shutting down the old server? I assume it’s not possible to have both servers running with the same domain at the same time.
Some downtime is fine, but manually changing the settings for each user feels impractical since we have hundreds of users. FYI, our end-users are on Outlook.