I wonder of spammers are just mass-creating Gmail accounts, getting hit with their own spam and flagging it as "non-spam" to confuse the filters... (If you are

I wonder of spammers are just mass-creating Gmail accounts, getting hit with their own spam and flagging it as "non-spam" to confuse the filters... (If you are in a position to build spamming infrastructure, you are certainly capable of setting automating email accounts for the purpose of unflagging spam.)