Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Standuply - Run daily standup meetings and track your metrics in Slack
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.
MeetNotes - Increase Productivity with Meeting Notes Tool. More effective minutes, Prepare Agenda, Collaborative Notes & Action Items.