Sender Policy Framework
SPF (Sender Policy Framework) is one of the foundational building blocks of email authentication. It allows domain owners to publish a list of authorised sending systems in DNS, helping receiving mail servers determine whether an incoming message originates from an approved source.
By defining which servers are permitted to send email on behalf of a domain, SPF reduces opportunities for spoofing and helps establish trust between senders and recipients. It also provides an important signal that is used by modern email security standards such as DMARC.
The average organisation sends email through far more systems than users typically realize. Business applications, cloud services and external suppliers may all send messages using the same domain.
If these systems are not correctly authorised, legitimate email may fail authentication and impact deliverability. At the same time, SPF helps receiving organisations differentiate between legitimate senders and unauthorised systems attempting to impersonate your domain.
In many organisations, SPF becomes one of the first sources of visibility into the true scope of their email ecosystem.
An SPF record is published in DNS and contains the servers that are allowed to send email on behalf of a domain. Whenever an email message is received, the recipient performs a series of checks against the sender's published policy.
The result forms part of the broader email authentication process and is often combined with DKIM and DMARC. Together, these standards help organisations establish trust in their email communications while improving protection against spoofing and phishing attacks.
Although SPF is conceptually simple, maintaining an accurate SPF record can become surprisingly complex. As organisations adopt new services and suppliers, the list of authorised senders often grows over time.
Typical challenges include:
Because email environments change continuously, SPF records often become outdated without anyone noticing. The result may be authentication failures, reduced deliverability or gaps in domain protection that remain hidden until an incident occurs.
SPF records provide the policy, but they do not tell you whether that policy accurately reflects reality. Understanding which systems actually send email on behalf of your organisation requires visibility into authentication results and email traffic patterns.
MailReport helps you understand the real-world impact of your SPF configuration. By analysing authentication results and reporting data, MailReport makes it easier to:
The result is greater visibility, better deliverability and stronger protection against domain abuse, helping organisations maintain control over an increasingly complex email landscape.