Huge Spam Problem

For the last week or so, our primary business email address has been slammed with some very peculiar spam (hundreds per day). Generally, the "From" email address begin with nine numbers (most of them unique) followed by: @qq.com (e.g., 123456789@qq.com). I have no idea where they're coming from -- and there doesn't seem to be much (if anything) in the way of body content.

Anyone else experiencing this -- or know what it's all about -- or why they're even being sent? Maybe it's just as an annoyance!! Fortunately, we have several spam blacklist filters in place on our local email client -- and they have been catching most of it. The filters we're using are third party spam filters. So, the very fact that these emails are being caught by these third party filters, indicates to me that we are not the only ones being targeted. I just don't get why we're getting these, why they are being sent -- what the sender's objective is in sending them

 

Thanks, Stapp, sounds exactly like the same thing.