All mail account Uniqueness

Tunning mail server design to let all account have Uniqueness.
let mail address more simple like SomeOne@au.edu.tw
and also can get mail from SomeOne@email.au.edu.tw or SomeOne@mail.au.edu.tw

如果你是真理大學資工或資管的學生(老師？)，且對此系統有興趣的話，歡迎跟我聯絡。