Kolab Community
Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.
20 Alternatives To Kolab Community
Citadel
Is a collaboration suite (messaging and groupware).
G Suite
Google’s encompassing suite of cloud-based business apps.
Google Calendar
Spend less time managing your day & more time enjoying it
Horde
Horde Groupware is a free, enterprise ready, browser based collaboration suite.
Kopano
Sharing & communication software for business
Lightning Calendar
Organize your life — it’s about time!
Mail-in-a-box
Mail-in-a-Box provides webmail and an IMAP/SMTP server for use with mobile devices and desktop mail software and also includes contacts and calendar synchronization.
Microsoft Exchange Server
Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft.
OX Open-Xchange
Open-Xchange Server 6 is the most advanced Linux based Groupware solution f.
Proxmox Mail Gateway
Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.
Rainlendar
Rainlendar - Customizable desktop calendar
Rainloop
RainLoop is a web based email client.
Roundcube
Web-based IMAP email client
SOGo
SOGo is groupware server with a focus on scalability and open standards.
Simple Calendar
A simple calendar with events (optional recurring and reminders), week numbers and a customizable…
Squirrelmail
SquirrelMail is a standards-based webmail package written in PHP.
Zimbra Collaboration Suite
Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more.
Zoho One
Zoho is an all-in-one online office suite.
iRedMail
A fully fledged, free email server solution, an open source project (GPL v2).
mailcow dockerized
An open source mailserver suite.