Quantcast Top 10k6,006 of 10,000
Quantcast Top 100k46,766 of 100,000
BuiltWith Top Million470,333 of 938,410
Entire Internet41,708,110 of 365,371,059
Log in or Sign up for Free to see SPF history back another year to January 2015. View plans for historical access back to April 2014.
The Sender Policy Framework is an open standard specifying a technical method to prevent sender address forgery.
Categories: Email Hosting Providers · Standard
We know of 41,708,110 live websites using SPF in our records.
View Website List
Get a list of websites using SPF
Sign up for Free
Log in or Sign up for Free to see additional categories and competitors.
Browse groups of technologies that we track.