Inbound email scrutiny and data loss prevention services.
http://www.websense.com/content/email-security-overview.aspx
Email Hosting Providers · Secure Email
Get access to data on 39,007 websites that are Websense Customers. We know of 22,551 live websites using Websense and an additional 16,456 sites that used Websense historically and 7,417 websites in the United States.
Get a list of 39,007 websites using Websense which includes location information, hosting data, contact details, 22,551 currently live websites and an additional 31,648 domains that redirect to sites in this list. 16,456 sites that used this technology previously and 7,417 websites in the United States currently using Websense.