Hello,
We have been seeing a rise in spam in general due to the holiday season. This is fairly common this time of year. You can take a look at our monthly "State of spam" report at the following site: The State of spam
As far as the type of spam that you are seeing, I would highly suggest that you submit these to Symantec. If you continue to see issues with this spam, a call in to support can tell if there is something wrong with either your configuration or with our servers letting these messages through. We would like this to be as transparent for you as possible and not cause you to have to do more work.
It is also fairly common to see changes in the spam landscape. A new type of spam, or new spam outbreak of a certain type can cause a slight percentage increase in volume of spam. I apologize for that.
Please let us know if there is anything else we can help with.
Tom
Title: Manually submitting spam and false positive messages to the Symantec Security Response Center