What is Sender Policy Framework (SPF)? SPF Explanation
SPF (Sender policy framework) is email validation system that was designed to protect against spoofing. How SPF works is quite simple where it will verify the Source IP from a sender then match it to DNS TXT records by using SPF contents. The figure above shows how SFP works in the working mail server system.
From the figure above can be seen that the email system that receives emails will check Sender-ID Framework for every received email by asking sender’s SPF record to DNS. There are only two results: Pass or Fail, when it goes to pass the email will be redirected to inbox folder of recipient and in the other hand the email will be redirected to Junk/Quarantine folder and , furthermore, can be dropped.
In fact, there is another result beside of Pass or Fail, that is Neutral. When the result is Neutral, there are several possibilities such as DNS propagation is still in progress or SPF was implemented without policy by the admin.
So what is the impact if we don’t implement SPF within our email system?
At most cases, if the recipient is really strict with the policy the received email will be considered as a spam or be blocked because it’s not trusted.
How To Check SPF?
After you’ve done with the configuration and DNS propagation has been completed, you can check it using mxtoolbox.com. Fill your email domain into SPF box search tool.
Hope it useful and cheers.