you change this in your mail settings, but depends what kind of mail you want to transfer. For example from all mail acounts you can transfer your contacts, but if you transfere for example from source in two different mail open source programs is not possible, but for contacts no problem, here all is very good done and for mail transfering on a new domain is not problem if you have here account all!!! Ciao
here all admins are doctors of information technology!!!
sorry for my english