I'm sure there are more than that, I don't feel like digging through my
mail server logs to find them.
Personally, I wouldn't rely on such a check alone to reject mail - maybe
in conjunction with white lists and/or greylisting, but that's a
*strong* "maybe".
But I'm sure you've heard "your server, your rules" before :D
Marc Perkel wrote: > I had a friend make an interesting suggestion. He said, "Why not
> check the sending IP to see if it can receive anything on port 25?"
> The idea being that a spammer might be sending on port 25 but can't
> receive anying on port 25.
>
> Has anyone try this?
