But will deleting your account remove your email from their (previously sold?) mailing list?
In the same way as using a unique identifier (middle initial, etc) when "registering" stuff with your physical name / address - so you can identify the source of spam , maybe you should use a disposable / forwarding / aggregating email address .
Of course now that the HF horse has bolted its a bit late to bar the email gate as it were.
Mind you, if you, like me, have friends + relations who don't and won't understand the concept of bcc, no matter how many times you tell them, then many of your email addresses are already out in the wild, never to fade away.
(E.g. how many times have you seen a "Here's a funny" with multiple fw's and cascaded email addresses ripe for harvesting.)