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.