Sender ID and SPF Failures

March 27, 2018 Contributors

In tools such as Mail-Tester you will sometimes see in the Authentication section a line that reads like the following:

These are relating to Sender-ID failures, not SPF failures. Unlike SPF, Sender-ID isn’t really in widespread usage, and more importantly, it focuses on the From (sender) domain, not the bounce (Return-Path) domain.

If you look at the Source of the message (in the "Click Here To View Your Message" section), you will see that the SPF did pass:

If you want to resolve this issue with the Sender-ID, you can do either of the following:

For more detail refer to this article at