I may need to do the same thing as I'm thinking of replacing my older 'perfect mailserver' setup with a new ispconfig box. There's about 100 users.
copy recursive old /home/vmail/domain to new /var/vmail/domain
Should I set the mail domain in ISPconfig beforehand?
What about the users & passwords? How could I import those into the ISPconfig setup? Or must I enter those one by one afterwards?