feedback loop from spam complaints?

I believe the Norton desktop spam filters report spam data back to Symantec. Is there a way to get a "complaint feedback loop" of this data from Symantec?

 

My company sends email newsletters to people who subscribe via our website. We put the unsubscribe link in the newsletters 3 times, but sometimes our subscribers who wish to cancel the mailings will flag the messages as "spam" rather than using the unsub link. Ironically, this is less effective than unsubscribing, because we don't get notified when the user flags our mailings as "spam." Therefore we would continue sending unwanted mail -- which we'd rather not do.

 

Feedback loops are not a new idea; we get them from Hotmail, AOL, Yahoo, Roadrunner, Comcast, Cox, etc... just about every major ISP in the US. But these only work for webmail accounts, for the most part -- no desktop spam filters that I know have a FBL mechanism.

 

Kaspersky is building one, I'm told. Does Symantec have anything like this in the works?