An MX record is a mail authority delegation. The History Department at a major university could delegate mail to be handled by the schools IT department and ne

An MX record is a mail authority delegation. The History Department at a major university could delegate mail to be handled by the schools IT department and need not be involved in the movement of a mail server from one IP to another. This decision was made in a time when running mail involved lots of external coordination and was best delegated to a single central group, whereas a simple web server could be spun up by a technical person within the History dept.