Thanks for the response Till.
To answer your question, yes actually I did check it with some standard security software I use to test common vulnerabilities. When I run my scan it turns up that my smtp is configured as a relay, which I assumed was because I'm using gmail to relay my mail. Once I enabled the fingerprint setting, however, the issue disappeared. I'm gathering that it's because it was not able to escalate privileges because there was that security enabled.
So do you have any suggestions?