Zimbra Collaboration Suite
Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more.
18 Alternatives To Zimbra Collaboration Suite
G Suite
Google’s encompassing suite of cloud-based business apps.
Horde
Horde Groupware is a free, enterprise ready, browser based collaboration suite.
Kerio Connect
KerioConnect is a commercial mail and groupware server.
Kolab Community
Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.
MDaemon Messaging Server
Low cost, easy to use Email Server software for virtual, on-premise, or hosted deployments for…
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.
Mailpile
Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
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.
PowerMTA
PowerMTA is an industrial-strength software for high-volume email delivery.
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.
Squirrelmail
SquirrelMail is a standards-based webmail package written in PHP.
Zentyal
Linux directory, domain, mail, gateway and infrastructure server for SMBs.
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.