grommunio Alternatives

Secure Email Gateway

On-premises, enterprise collaboration solution for documents, emails, calendars and more.

Auto arrange all your app windows, whether on one screen or many with a single click!

Try for free freemium $39.99 / Annually (One PC, One Year)

Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online

Fortinet Email security is designed to block ransomware, phishing, and other cyber threats seeking entry via incoming email and outgoing messages don’t improperly leak sensitive data.

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

Open Source

Internet Information Services is a web server for Microsoft Windows

Use this program to "Unspam" your mailbox(es).

Open Source

Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.

Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.

Say goodbye to phone and email tag for finding the perfect meeting time with Calendly. It's 100% free, super easy to use and you'll love our customer service.

Sharing & communication software for business

Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.

An open source software implementation of the Java Servlet and JavaServer Pages technologies

Open Source