Voting Question: How can I stop these returned emails that I haven’t even sent?

I think some spammer has use my email address for their return mail because I’m getting tons of return mail that I have not sent. Is there any way to find out how to stop this? I don’t want my account to be flagged as a spam account because I have had this same address for like 10 or more years.
Any help would be greatly appreciated
I have a firewall, trendmicro, and maleware bites installed. When I scan, it shows a clean slate. The laptop is only a couple months old so it doesnt have a lot of files on it.