Mail server_SPF records - SomethingWithHorizons/mailserver GitHub Wiki

The Sender Policy Framework (SPF) is an open standard specifying a technical method to prevent sender address forgery.

DNS configuration

Set-up the following DNS record at your domain registrar:

Domain	Type	Content
@	TXT	v=spf1 mx -all

:information_source: The SPF record above tells that we use version 1 of SPF, that only the resolved MX address is allowed to send e-mails and that everything else should be blocked (-all).

:information_source: Available options are explained on the Openspf site.