These numbers do not include departmental mail servers. These distribution lists are used by professors to send out assignments to their classes and to continue class discussions outside of normal class hours. They are used by Clemson colleges and departments to reach students and employees. School organizations use them to keep in touch with their members and announce activities. Email lists are used for all kinds of collaborative efforts at Clemson.
Email lists are great because they save time and money.
And we rank number one in the world for number of lists maintained.