The Sender Policy Framework is an open standard specifying a technical method to prevent sender address forgery.
http://www.open-spf.org/
Email Hosting Providers
Get access to data on 143,099,829 websites that are SPF Customers. We know of 107,596,423 live websites using SPF and an additional 35,503,406 sites that used SPF historically and 7,669,774 websites in the United States.
Get a list of 143,099,829 websites using SPF which includes location information, hosting data, contact details, 107,596,423 currently live websites and an additional 5,008,975 domains that redirect to sites in this list. 35,503,406 sites that used this technology previously and 7,669,774 websites in the United States currently using SPF.
Countries
Financial
Group
Region