Zimbra - Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.
Microsoft 365 - Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online
mailcow - An open source mailserver suite.
Apache OpenOffice - Apache OpenOffice is an open source, office document productivity suite.
Roundcube - Web-based IMAP email client
SoftMaker Office - SoftMaker Office is one of the most powerful and reliable office suite that is fully compatible with the MS Office Suite.