Rather than have full blown email, how about text only, no attachments, limited to 4096 characters, being directed straight to the users messagebox? ie. firstname.lastname@example.org would just pump a text message, max 4K text, to my private message inbox. I could even send stuff to myself that I wanted to upload into threads or the wiki and a later point. Actually, attachments WOULD BE NICE, but I understand may need addition vBulletin features. I would suggest limiting attachments to a size of, say, a BIOS file, not more.