You've been
Joe-jobbed
Someone is sending spam and using your address as the return.
If you will copy and paste the ENTIRE headers and content of one of them in a PM to me, I may be able to help you find who's responsible. I am an avid-anti spammer and LOVE hunting spammers in my free time.
As with Tervuren, I also make a specific email account for everywhere I purchase something or sign upo for something, but I take it one step further.
For example, if I buy something from Amazon.com I will start an email address such as Amazon_dot_com@wherever. Spammers cannot auto-generate the underscore when generating addresses to spam. If the account gets spam, it is
absolute proof that the company or website has sold or otherwise distributed the email address. I have hundreds of addresses like that using Hotmail.
If we discover who Joe-Jobbed, you, I suggest you contact
Dietrich Biemiller who is one of the most prominent spam-fighting attourneys in the USA.