Kolab Now Alternatives [Page 3]

Horde Groupware is a free, enterprise ready, browser based collaboration suite.

Sharing & communication software for business

The #1 email warming service to improve your deliverability by generating realistic and meaningful engagement to your emails. Easy-to-use solution to help you land in the main inbox instead of the spam folder.

Visit website paid $19.5 / Monthly (Pro)

Email, calendars, and contacts to highest standards of security, privacy and reliability.

paid Free Trial $3.0 / Monthly (per user)

Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.

A fully fledged, free email server solution, an open source project (GPL v2).

Open Source

All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail.

Open Source

Modoboa is a mail hosting and management platform including a modern and simplified Web User Interface.

Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Simple and easy-to use PHP e-mail client.

SquirrelMail is a standards-based webmail package written in PHP.

Open Source

Open-Xchange Server 6 is the most advanced Linux based Groupware solution f.

Self-hosted server for the ProtonMail client.

CryptPad is a collaborative office suite that is end-to-end encrypted and open-source.

Open Source freemium €5.0 / Monthly (Personal 5GB)