We are in trouble please help - Someone has decided to use our server as a Spamming gateway. How do I stop them?
The server is currently on overload normally a couple of hundred mail meassages go through it every day - that now up to thousands. There must be some set ups to restrict this!
For example as all users accessing it are email@example.com - is it possible to only allow those users to send mail from the server (I cant think why we would need to allow access to anyone else)although I guess the downside if that was done presumably we'd end up with 1000's of mails that did'nt reach their destination.