Top Alternatives to Zimbra Collaboration Suite

Zoho is a comprehensive suite of online business applications offering solutions for CRM, office productivity, collaboration, IT management, and more. It provides a unified platform to streamline various business operations.

Roundcube is a free and open-source webmail client providing a modern, user-friendly interface to access and manage your email via IMAP. It is designed for easy self-hosting and offers extensive customization options.

Kolab Now is a comprehensive, secure, and privacy-focused web-based email and groupware suite. Built entirely on free and open-source software, it offers a full range of collaborative tools including email, calendar, contacts, and document management, prioritizing user data ownership and security.

Kolab Community is a comprehensive, free, and open-source groupware suite designed for collaborative work. It provides integrated email, calendar, contacts, and tasks functionalities, empowering individuals and teams to communicate and manage their data efficiently and with a strong focus on data privacy.

Kopano is a versatile open-source groupware suite offering email, calendaring, contacts, and online collaboration tools for businesses and organizations. It provides flexible deployment options, including on-premises and hosted solutions, with strong focus on data privacy and security.

Horde Groupware is a free, web-based suite of applications designed for collaboration and productivity. Built on the robust Horde framework, it offers a comprehensive set of tools including webmail, calendar, task management, and note-taking, providing an integrated platform for individuals and teams.

Microsoft Exchange Server is a robust mail and calendaring server designed for businesses of all sizes, providing enterprise-grade email, calendaring, and contact management capabilities.

iRedMail is a comprehensive, free, and open-source mail server solution designed for ease of deployment and maintenance. It bundles popular components like Postfix, Dovecot, and Roundcube, providing robust email, calendar, and contact management capabilities.

mailcow is a comprehensive open-source mail server suite built on Docker, providing a robust and secure platform for self-hosting email. It integrates various components like Postfix, Dovecot, and SOGo into a single, easy-to-manage system.

OX Open-Xchange is a comprehensive web-based suite designed for communication, collaboration, and office productivity, offering features like email, calendaring, task management, and document sharing, seamlessly integrating across devices.