34 Like Kolab Community Good alternative? YES NO Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite. Free Open Source Linux Web Self-Hosted CalDAV CardDAV Real time collaboration Support for WebDAV Add a feature
2 Like Scrollout F1 Good alternative? YES NO Scrollout F1 is a free self-hosted email gateway designed for Linux & Windows administrators without advanced email security experience. Free Open Source Linux Self-Hosted No features added Add a feature
15 Like Microsoft Exchange Server Alternative? YES NO 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... Commercial Windows Web Real time collaboration Add a feature
13 Like Zarafa Good alternative? YES NO Open Source Collaboration, providing integration with your existing Linux mailserver, native mobile phone support, Outlook "Look & Feel" webaccess and... Commercial Mac Windows Linux Web Real time collaboration Add a feature
1 Like Poste.io Good alternative? YES NO Full featured solution for your Email server. Native implementation of last anti-SPAM metods, webmail and easy administration included. Free Personal Linux Support for Docker Add a feature
3 Like Mercury Mail Transport System Alternative? YES NO The Mercury Mail Transport System is a mail server that sends and receives messages on behalf of a group of users on a machine or local area network. Messages from the... Free Personal Windows No features added Add a feature
4 Like Citadel Good alternative? YES NO Is a collaboration suite (messaging and groupware). It is designed to run on open source operating systems such as Linux or BSD. In order to modernize the Citadel... Free Open Source Linux Web Real time collaboration Add a feature
5 Like Expanding Communication Alternative? YES NO Turnkey Solutions for the Enterprise Cloud Installation, Configuration, and Management tools for enterprise email, collaboration, messaging, video conferencing, file... Commercial Linux CalDAV Add a feature
0 Like Proxmox Mail Gateway Good alternative? YES NO Proxmox Mail Gateway helps you protect your business against all email threats like spam, viruses, phishing and trojans at the moment they emerge. The flexible... Commercial Linux Self-Hosted No features added Add a feature
1 Like PowerMTA Good alternative? YES NO Email gateway application (SMTP server) that makes it easy for senders to adopt the latest authentication specifications ( SPF and DKIM) to comply with changing ISP... Commercial Windows Linux Self-Hosted No features added Add a feature
8 Like Axigen Good alternative? YES NO Axigen provides a multi-tenant, fully integrated, multi-platform, all-in-one email, calendaring and collaboration messaging solution. It grants extensive branding... Commercial Mac Windows Linux BSD Self-Hosted Microsoft Office Outlook CalDAV CardDAV Delegated Administration Multiple languages Real time collaboration Shared folders ... White-labeled Add a feature
1 Like iMail Good alternative? YES NO Fast, safe, heavy mail solution. Web-client access, LAN or WAN self-hosted server, maintenance-free design. No Windows server and database server required, unlimited... Free Windows Self-Hosted No features added Add a feature
5 Like SophiMail Good alternative? YES NO SophiMail is a fully-featured email and collaboration server solving the most critical email issues: maximizes Privacy, Portability and Cost efficiency, Admin & User... Free BSD VirtualBox Self-Hosted KVM (Kernel-based Virtual Machine) HyperVM Citrix XenServer VMware vSphere Hypervisor FreeBSD ... Microsoft Hyper-V Server Daily Backup Indexed search CalDAV CardDAV Privacy focused Private messaging ... Schedule Backup Security focused Selective folder sharing Shared folders Team collaboration Two factor authentication Unlimited users Add a feature
7 Like OpenChange Good alternative? YES NO OpenChange aims to provide a portable Open Source implementation of Microsoft Exchange Server and Exchange protocols. Exchange is a groupware server designed to work... Free Open Source Linux No features added Add a feature
4 Like Blue-Mind Good alternative? YES NO Blue Mind is a complete solution of company messaging, calendars and collaborative work. It aims to enable you to work daily with comprehensive, useful, efficient and... Free Open Source Linux No features added Add a feature
