I'm looking for a way to require those wanting to send emails to folks on our Ex03 to have to register to do so, in the order of They send mail, get a reply back asking them to go to a site to register or send to a special requesting address, they register, and whoever the initial mail was for would have to allow or deny them the request. Of course once they are on the whitelist they are ok. And also users can be manually added also. The purpose being to cut down on spam and unnecessary messages. This functionality is not my idea but a managers. Currently the SBS03 box is open to the outside for mail only, and I really don't want to open up IIS to the outside. If whatever this was could have it's web pages on a generic hosting co's webspace I would be much happier. Can anyone point me in the right direction of something that will do this?