Moll, if you haven't already got Spybot and AdAware on your computer put them on. The important thing is to keep them updated and run them often. Worth trying in case you have have anything lurking on your pc that is sending out info.
You could try contacting cobbcollaborative.org, which is based in Cobb County, USA, and ask to be removed from their list.
Or you could just "block sender".
Also, most anti virus software and ISP's will scan incoming/out going mail for virus'.
But as already stated in Timid Toads reply, if in doubt, DELETE.
P.S. trendmicro anti virus is good, althou