A. A server is said to have an open relay if it allows people who don't normally have an account with that provider to send email through thier server. For example, if you are not a MIS customer and if you were able to send email from one of our mail servers, that server would have an open relay. Open relays are bad for a couple of reasons. One is that if a spammer sends mail through an open relay, it looks like it originated on that server even though the sender doesn't have an account. Another is that with a mass mailing, the server can slow down drastically or even crash. And of course, abusing an open relay as most "spammers" do, is an unauthorized and possibly illegal use of another company's resources and bandwidth.