We require you to give a valid email address when you register so that we will have some way to contact you if there are ever any problems with your posts or your account.
The Chronicle of the Horse does NOT sell or distribute those email addresses.
From time to time, I might send out an email to the entire BB membership -- to let you know about a service outage, a special feature, etc. Those are the only emails you will receive from us, and they are very infrequent. (You can opt out of those emails as well, by checking the box on your profile requesting not to be emailed by the site administrators.)
Now, if you choose to display an email address on your profile (by entering an address in the "display email" address on your profile), you MIGHT get some "spam" email. To date, this has not been a big problem on this forum.
But if you're concerned, you can "doctor" your display email address to fool automatic emailers. For instance, if I put "COTHCatHerder_no_spam@yahoo.com" down as the "display email" on my profile, it will be easy for BB users to see that it's not a real email address -- that they need to delete the "no_spam" to get my real email address.
If you're concerned about spam, but still want to have an address listed on your profile so other BBers can contact you, a no-spam address is a good idea. Also, consider using a free email service like Yahoo or Hotmail, so you can keep your personal address personal!
Make sure you do NOT put a "no-spam" type address down as the PRIMARY email address on your profile -- the BB sends a confirmation email to that address, and obviously it won't arrive if it's not a valid address, and then you won't be able to post.