Sender Policy Framework

Why did SPF cause my mail to be rejected?

What is SPF?

SPF is an extension to Internet e-mail. It prevents unauthorized people from forging your e-mail address (see the introduction). But for it to work, your own or your e-mail service provider's setup may need to be adjusted. Otherwise, the system may mistake you for an unauthorized sender.

Note that there is no central institution that enforces SPF. If a message of yours gets blocked due to SPF, this is because (1) your domain has declared an SPF policy that forbids you to send through the mail server through which you sent the message, and (2) the recipient's mail server detected this and blocked the message.

You can pretend that a message bounced with:

How can I reference this web page for explaining SPF results?

This web page is a public service of the SPF project. SPF implementations can (and do) use it to help explain the results of SPF checks by presenting to users a parameterized link to this page. See the "Why?" page documentation for details on how this works.