The Sender Policy Framework (SPF) is a system used to prevent email spoofing by verifying that an email comes from an authorized server.
SPF helps the receiving email servers verify that an email claiming to come from your domain is actually sent from an authorized server.
How SPF works
Here is how the sender policy framework works:
You add an SPF record in your domain’s DNS zone. That record lists the servers allowed to send emails for your domain.
When you send an email, the receiving server checks your domain’s SPF record.
If the sending server is listed, that is a Pass. If not, that is a Fail. The email may be rejected or marked as spam.
