Sender Authentication: What Is It, and How Can It Help You?

Later, as real-time reputation systems gain acceptance, sender authentication will function to properly verify sender identity, so ISPs can then use reputation systems as reliable guides to determine from which senders they wish to accept messages.

IF: What standards have been developed for sender authentication?
Guerra: Sender authentication technologies are still new, and for the most part, their standard usage is still being determined. While many ISPs are using some of the sender authentication technologies, most agree it is too early to begin discarding incoming messages based on sender authentication. Some of the largest ISPs have indicated they will likely first begin providing their users an indicator for messages that have failed sender-authentication tests.