Just a last post from me: is there any chance that a whitelisted IP address (whitelisted on our local email server for the remote to forward email to us as we plan to permit Tcp25 incoming for this whitelisted IP while the rest of the emails have to go to our ProofPoint) could have been spoofed?
If there's such a possiblity, can list a few URLs/links that illustrate & explain such spoofing? I hear conflicting internal suggestions
