SPF

Rate this page:
SPF is an email authentication standard that helps ISPs better identify legitimate email senders.

Sender Policy Framework (SPF) is an open standard for authenticating email that was originally developed by AOL. SPF attempts to ensure that the IP address from which a message was sent is approved to send email by a domain’s owner.

Imagine you own the domain example.com. You also have an email server that uses the IP address 127.0.0.1. You may use an SPF record to designate this IP address, 127.0.0.1, as the only IP allowed to send email using an example.com email address. When an email server receives a message from sender@example.com, it can check the IP address that delivered the message. If the IP is anything other than 127.0.0.1, the SPF check will fail, informing the receiving server that the message is from an unauthorized source.

SPF Records

An SPF record is implemented using a TXT DNS record. The TXT record has several values, the first being v=spf1. This first value indicates that the TXT record is a version 1 SPF record.

The remaining mechanisms in an SPF record are "INCLUDE," "A," "MX," "IP4 and IP6," and "REDIRECT." These mechanisms specify either an approved IP address directly or a domain that will resolve to an IP address.

SPF is one of several effective ways to check an email’s legitimacy, and this article provides only a brief overview. For more information about SPF, see SPF Records Explained.

Rate this page:

Thank you for your feedback!

We are always striving to improve our documentation quality, and your feedback is valuable to us. How could this documentation serve you better?

Sending your feedback...
🎉 Thank you for your feedback!
Something went wrong. Please try again.

Thanks for your feedback!

Refer us and get $10 in 3 simple steps!

Step 1

Get link

Get a free personal referral link here

Step 2

Give $10

Your user signs up and upgrade using link

Step 3

Get $10

1,250 free SMSes
OR 1,000 free voice mins
OR 12,000 chats
OR more