MirrorFly - World's Most Scalable Voice, Video & Chat SDK for Small, Medium & Enterprises
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
chatwee - Group chat app for online communities. Used wherever visitor interaction and engagement are key to the site's functioning.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
echofin - Echofin helps communities grow, engage and monetize their following in ways no other platform has done so far.
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.