Requirements
MSH Zimbra Rules installs directly on the server running the Zimbra MTA. It ships as a single package containing two services: the milter engine that processes mail and the web admin UI where you manage rules. Both are administered from a browser, so no additional client software is required.
Requirements
| Component | Requirement |
|---|---|
| Operating system | Linux with systemd (Ubuntu is the documented and tested platform) |
| Architecture | x86_64 |
| Mail server | Zimbra Collaboration Suite with its bundled Postfix MTA |
| Java | Java Runtime Environment (JRE) 21 or later (OpenJDK recommended) |
| Memory | 2 GB of free RAM recommended (each of the two services runs with a default maximum heap of 1024 MB) |
| Disk space | A few hundred MB for the application, plus space for the database, diagnostic logs and stored attachments under /opt/msh-zr |
Notes
- The application runs on the Zimbra server itself in a typical single-server deployment. The milter listens on port
7080and must be reachable from the Zimbra MTA; the web admin UI listens on port7081and must be reachable from your browser. - Both services run as an unprivileged system user (
msh) and do not interfere with Zimbra's own processes. - Any modern Linux distribution with systemd should work. Installation commands in this guide are shown for Ubuntu; adjust package manager commands for your distribution where needed.
What's next
- Java - install Java 21 on your server
- Server installation - install and start the MSH Zimbra Rules services