We do not sell, lease or otherwise distribute our members email addresses. Never have, and never will as long as I own the site. I've turned down some significant offers for mailing lists.
You will get some email from us however.
If you subscribe to a thread, you'll get emailed notice when it is replied to.
If you turn on the feature, you'll get regular digests of content, as well as notification of PMs.
If you have it enabled, other members can email you through an anonymous form. Emailing someone with this form will give the receiver your address. If you reply to it, they will then have your address.
If you post it somewhere, it's publicly visible, however searching the members list, reading your profile, or private messaging you will not reveal your email address.
Spammers forge headers all the time. Some less developed anti spam filters incorrectly look at the "from" field rather than the actual sending server.
If someone is abusing our "email a member" feature and spamming you, we want to know about it. We will take whatever actions we must to prevent any abuse of our service, including legal if necessary to block such abuse.