UPDATE 2: It was actually the forum that was making the spam, I just had to disable "Email this Page" on the "Thread Tools" menu.... Normal service has been resumed. UPDATE: It started happening again, I will have to take the email server down for a few days until I get to the bottom of it... Someone got into the email server and used it to send thousands of mass spam emails; but it does not look like any spam was sent to empires forum members. However, as a result of this a lot of email providers are going to recognise emails from the forum as spam now, so check your spam folders if you don't get any forum emails any more. EDIT: As and unrelated side note: I fixed some problems with the empires wiki relating to tmp dirs and re-enabled image uploads there too.
When did this happen? Reported post mails always went automagically into my spam folder since I have ascended to moderator.
So they had a chance to see the list of email addresses of empiresmod forum users, btw? Or they only had access to send the emails? Just asking.
Well after finding the cause of the spam it wasn't the anything had been compromised or hacked; it was that someone was spamming a button on the forum via a script (like 10,000 emails at once). More specifically the "email this page" button under "thread tools". Then it was just a case of changed the permissions of regular user and not logged in users to deny use of that button.