DuoCircle - DuoCircle provides enterprise spam filtering and email management solutions.

SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.

Hiver - Manage Customer Support, Sales and Projects right from your Gmail inbox. Collaborate with Shared Labels, Shared Contacts, email notes, email reminders and email templates

Sanebox - SaneBox is a cloud-based service that allows users to filter and manage their emails.

Nylas Mail - The Nylas Cloud API powers your application with email, calendar & contacts features. Built-in features for better email, calendar, and contact management.

ZeroSpam - Cloud email security & anti-spam solution