Sender Policy Framework (SPF)

[Mischback]

SPF is not really part of the (technical) server setup, as it is defined in the host's/domain's DNS setup.

However, it should be considered while setting up the mail server.

Idea

• Include check for a valid SPF DNS record in the validator script

References

• https://www.spfwizard.net/
• https://workaround.org/bullseye/prevent-spoofing-using-dkim-2/
• https://thomas-leister.de/mailserver-debian-buster/#spf-records