HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
MailStore - MailStore Home - A 100% free single-private-user desktop solution
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
MailSteward - MailSteward : The Ultimate E-mail Manager for Mac OS X
Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.
Gmvault - Backup the emails in your Gmail account.