1 - create the new domain with the same name as the old domain?
2 - create all the accounts of the old server to new server
3 - may be the two domains with the same name but with IPs different in the same network?
4 - to create the new domain with a different name and then creates a virtual domain with the name of the production server?
5 - Installing IMAP on the old server to use the imapsync brings some malfunction in the server production?
6 - the migration scripts I run on the old server or new?