This page is primarily for configuring the SPF (Sender Policy Framework) DNS record, which is used by other mail servers to ensure that email claiming to be from a mailbox in this domain actually was. This prevents spammers and worms from faking source email addresses, thus allowing them to be more easily blocked.

A domain's SPF record specifies the mail servers that are allowed to send email from that domain, and a policy to apply to other senders. Recipient servers can then lookup this record, and compare the address of the system sending email with the allow list for the sender's domain.