Out mail server was recently blacklisted. After lots of investigating we have narrowed the issue down to us being blacklisted as we are generating backscatter.
We run Exchange 2007 (on a SBS 2008 server). We run Symantec Mail Security 7 as our mail security product.
The only way I could prevent us from being continually re-blacklisted was to disable the Symantec Premium Anti-spam feature.
I now need to look at re-enabling it in such a way to reduce incoming spam and also avoid the backscatter issue.
I am a little unclear exactly how the anti-spam function works and would ask if someone can answer a few newbie questions for me.
Question one is if I set Premium anti-spam to reject Spam Messages/Suspected spam messages and SCL greater than 6/suspected spam, will the sender receive any warnings from our server that there message has been rejected?