SPF is an email authentication method designed to prevent spammers and scammers from sending emails that appear to come from your domain. In other words, it’s a way to verify whether an email claiming to be “from you” actually came from an authorized source.
How it works
SPF works by using DNS (Domain Name System) to publish a list of IP addresses or servers that are allowed to send email on behalf of your domain. When a receiving mail server gets an incoming message, it checks the domain in the “Return-Path” against that SPF record.
If the sending server is not on the list, the email fails the check and can be flagged, filtered, or rejected.
For example, if your SPF record only allows Gmail servers to send emails on your behalf, and someone tries to spoof your domain from a different server, that message will likely be blocked.
Why it matters
- Protects your domain from spoofing
Prevents bad actors from impersonating your domain and damaging your brand’s reputation. - Improves email deliverability
Inbox providers are more likely to accept your emails when they see an SPF record is properly configured. - Works together with DKIM and DMARC
SPF is one piece of a stronger email authentication puzzle. When used with DKIM (to verify the contents) and DMARC (to set enforcement rules), it gives your domain much stronger protection.
Pro tip: Your SPF record must be set up correctly – having multiple conflicting SPF records or missing authorized services (like your email marketing platform) can cause legitimate emails to fail authentication and end up in spam. Use tools like MXToolbox or your email provider’s documentation to double-check your setup. If you’d like to learn more about SPF, check out our blog here.
