SpamAssassin - Use this program to "Unspam" your mailbox(es).
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.
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.