Mailspring - Mailspring is a mail client for Mac, Windows and Linux.

Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.

Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.

DownToMeet - DownToMeet is a platform to organize, find, and attend group events.

eM Client - eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.

Mighty Networks - Mighty Networks enables entrepreneurs, organizations, and companies to create and grow a community-powered brand.