This is a sad part about getting larger... at a certain point you get targeted by spammers. The latest spamming invention is actual real people just going through profiles and forums and harvesting email addresses... they'll even just sign up for user accounts and send private messages.
Sadly there is very little way for us to stop this - we take every care to make sure that the site is secure, so know that its not a vulnerability there that causes it.
To stop this email, you should never post your email address publicly. I do post mine and have to accept the spam because I want you guys to be able to reach me. So if I'm posting in a thread and I say email your entries to firstname.lastname@example.org - blammo spamorama.
Likely where most of you are getting it is from your profiles (you can edit it here http://newschoolers.com/web/members/profileupdate/member_id/1706/).
There is a public contact section where you enter email, ICQ, AIM, etc - and this information is available to the public. We wanted NS to be free and open, but perhaps in the future we should make certain public and private profiles.
If you go to that page and delete the email address there it won't affect you getting the mailout, or the site contacting you with notifications. This is just what is displayed in your profile - and likely what the spammers are harvesting.
Be really careful about posting your email in threads too... this is a very common way for spammers to harvest email.
Sorry about this guys, we'll work on ways to address spammers over the summer.