Due to the adoption of blacklists which identify senders of Unsolicited Commercial Email or spam and block all email from those sources, it is necessary to make sure that all mail goes through authorized pathways. This prevents rogue programs from sending out unsolicited email (spam) directly to the Internet.
Without such a policy, the University runs the risk of having the entire .mst.edu domain of email addresses placed on an email blacklist. This would prevent email from flowing to sites that utilize the particular email blacklist. Removal of an entry from a blacklist is very difficult.
The University has been blacklisted in the past and suffered failed mail delivery to major Internet Service Providers for several days before the problem could be rectified.