MailStore - MailStore Home - A 100% free single-private-user desktop solution
PersistIQ - It takes multiple touch points before a lead engages. PersistIQ automates the tedious parts while preserving the key human elements of sales
MailSteward - MailSteward : The Ultimate E-mail Manager for Mac OS X
Upscale - Crush your revenue goals faster with Upscale, the sales engagement platform
Gmvault - Backup the emails in your Gmail account.
Autoklose - Machine learning assisted email follow-up