SOGo is described as 'is groupware server with a focus on scalability and open standards' and is an app in the Office & Productivity category. There are more than 50 alternatives to SOGo for a variety of platforms, including Online / Web-based, Windows, Linux, Mac and Self-Hosted solutions. The best alternative is Roundcube, which is both free and Open Source. Other great apps like SOGo are Wrike (Freemium), Rainloop (Free, Open Source), Mailpile (Free, Open Source) and monday.com (Paid).
Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft. It is part of the Microsoft Servers line of server products and is widely used by enterprises using Microsoft infrastructure solutions.
GQueues is the premier task manager for Google and G Suite users. GQueues tracks millions of tasks for people, companies and organizations worldwide. Designed with a focus on simplicity, GQueues stays out of your way so you can get things done.
All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail. Cypht does not replace your existing accounts - it combines them into one. And it's also a news reader :).
5pm is a web based project management application with a smart customizable interface. Email integration, iCalendar and RSS feeds, Timeline view and Reports are just a few features to mention. Free trial (no credit card required) is available.