We had an incident yesterday.
Emails coming in and going out were being affected. Message headers and the body text were being seperated. Sometimes the user would recieve a blank mail but sometimes the header would be recombined with the body text from another random email. This showed up how weird some of the emails that get sent are. The head of IT got details of someones last bondage session.
We isloated the problem to our Surfcontrol Spam filter. When we took that out of the loop we were able to bring everything back up.
According to Surfcontrol we haven't applied 1 patch which fixes a vulnerability to a virus (don't have the name to hand) which affects some of the filter rules but they'd never heard of it having the effect of mixing emails.
Anyone ever seen anything like this?