Hello, I am having problems and I have just realised the cause. It appears as though my servers IMAP/POP is being used to send out hundreds of thousands of emails. I can't actually see any of the ones being sent out though. I just logged into Plesk and saw that the IMAP/POP usage for this month is 400GB. I naturally have root access but I am not sure how I can stop this from happening? It is causing my server to crash with all of the massive traffic being sent through my mail server. Can someone advise how I can troubleshoot and detech and resolve the problem of my mail server?
Originally, I thought that maybe my server was bouncing mail from an open SMTP server... But then I realised that it is IMAP and POP that is showing the usage NOT SMTP... sooo? I was going to just block port 25... but SMTP only shows 25Mb worth of usage.