Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.