Junk Email Filter - Junk Email Filter is a front end spam filtering and virus blocking service for email servers.
Polymail - Native email app for email productivity.
Covideo - Covideo is a Video Email Platform for Businesses that enables companies to communicate quickly and effectively with their customers.
New Gmail - The new version of Gmail web
Outlook4Gmail - Outlook4Gmail provides easy synchronization of your Outlook and Google accounts
Airmail for iOS - One of the best Mac email clients, now on iPhone