Junk Email Filter - Junk Email Filter is a front end spam filtering and virus blocking service for email servers.
HEY - Email at its best, new from Basecamp.
Covideo - Covideo is a Video Email Platform for Businesses that enables companies to communicate quickly and effectively with their customers.
InstAddr - Disposable email address application.
BlueMail - BlueMail is an email management app for Android, iOS, and Windows.
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.