[dc3dreamer]

With regard to spamming - check out Domain Keys and DKIM (forget Microsoft's competing proposal, it's dying/dead). Here's an easy to understand explanation

http://antispam.yahoo.com/domainkeys

The 'key' is, as I was talking about earlier, the mail server manages this, rejecting messages when the From: address is forged. One could impose the requirement that all incoming posts to their VB forums be DKIM-authenticated. This requires that the sender's mailserver support DKIM as well as the server hosting the VB forum mailboxes. I don't see a practical way of handling forged From addresses winthin individual clients (short of signing and verifing signatures, requiring everyone to have certs, etc.). Think of DKIM as a sort of driver-client architecture, where the common problem of address authentication is solved at the common points, the mail servers.

Don't burn time trying to do something in you stuff. Yahoo! uses DK in Yahoo! groups, so expect it to be widely available.