Wikipedia
Mailroute
MailRoute Inc. is an email security provider applying advanced methods for ‘washing’ email for viruses and spam. The service works by taking over the role as a middleman in the DNS MX record between the open Internet and the email server. The service also protects against email server outages by temporarily hosting incoming emails until the email server is ready to receive messages again.
Founded in 2003 by Thomas A. Johnson, MailRoute is a privately held company headquartered in Manhattan Beach, CA. Thomas A. Johnson was also the original founder and CEO of FrontBridge, the email filtering company that was acquired by Microsoft in 2005.
The service received some attention in 2010 because of its sponsorship of TWiT.