RingCentral - RingCentral is the leading provider of cloud-based communications and collaboration solutions for small business and enterprise companies
MailStore - MailStore Home - A 100% free single-private-user desktop solution
Dialpad - Switch is a cloud-based phone system built for Google Apps users.
MailSteward - MailSteward : The Ultimate E-mail Manager for Mac OS X
Aircall - Aircall is a call center software of a new generation designed for fast growing companies. Setup instantly and integrates to your CRMs
Gmvault - Backup the emails in your Gmail account.