To add other protocols would greatly increase management costs perhaps to the point of being effectively unmanageable. This policy is accepted within the University and does not cause any problems. A common network protocol is fundamental to interoperability. See RFC 1600 for a list of the official standards that must be adhered to in order to qualify as an IP connected host. All electronic mail on the Internet, AARNet and Sydnet is delivered using this protocol.
Management overhead is reduced if only one mail protocol is supported.
SMTP is accepted as the de-facto mail delivery protocol standard within the University. RFC 1425 SMTP Service Extensions. RFC 1427 SMTP Service Extension for Message Size Declaration. J. Klensin, WG Chair, N. Freed, Editor, K. Moore. Electronic mail traditionally only contained simple text.