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 37,170 websites that are Websense Customers. We know of 14,519 live websites using Websense and an additional 22,651 sites that used Websense historically and 4,920 websites in the United States.
Get a list of 37,170 websites using Websense which includes location information, hosting data, contact details, 51,147 currently live websites which includes 36,628 domains that redirect to sites in the list. 22,651 sites that used this technology previously and 4,920 websites in the United States currently using Websense.