Need to know why SMG classified messages as spam.
The SPAM message decision is based on the characteristics derived from pattern matching, filters, and heuristic algorithm analysis based on the Broadcom global spam database.
Symantec does not divulge which spam rules are triggered on an email. This would allow people with malicious intent to reverse engineer our spam detection technology, and eventually circumvent the detection so the product stops working for you.
The Product Support team does not have access to modify or change the SPAM detection decision. If a legitimate email has been incorrectly given a verdict of spam then should be submitted to Symantec Security Response for analysis and filter review.
For more details about false positive spam, please refer to the following article: Submit false negatives (missed spam) or false positives (legitimate email) to Symantec Security Response