Download the grommunio appliance and apps.

Quick Start

A short guide that can be used as a checklist for downloading, installing and starting the grommunio appliance.

  1. Download the installation image.
  2. Use the grommunio installation medium for the installation and the quick start of the configuration by going through the following chapters.
  3. Apply for or create SSL certificates for the secure, encrypted operation of the most important services.
  4. Create the appropriate DNS records with a reasonable configuration (A, MX, TXT and CNAME records).
  5. Configure the grommunio appliance by running grommunio-setup.

Minimum requirements

The following minimum requirements apply to the installation of grommunio (or the use of the grommunio appliance):

  • Server or virtual machine (VMware, XEN or Hyper-V) with at least:
    • 4 CPU cores
    • 4 GB RAM
  • Correctly configured DNS entries, at least 2, for example:
  • SSL certificate with all DNS names contained, alternatively wildcard certificate for the entire domain. (Let’s Encrypt can be created with grommunio-setup)

If you already have a certificate, it can be used, but it must be in PEM format, with a file containing the certificate chain and server certificate, and a separate key file.


It is strongly recommended that you have correctly set the relevant DNS entries, otherwise AutoDiscover cannot determine the server.
Optional requirements

  1. MX DNS records for the delivery of incoming emails.
  2. At the time the certificate is generated by Let’s Encrypt, port 80 must be accessible for all defined DNS entries.

Download & Installation

  1. Download the installation image
  2. Load the image file for installation on the server on which grommunio is to be installed.
  3. Start the installer and select “Installation” at the boot prompt to install grommunio.


Please note that the installer asks you to confirm the installation. Please note that this will overwrite and delete the installation target!
After installing the grommunio appliance, grommunio is ready for the setup.


After the installation and restart of the grommunio appliance, the server displays the grommunio cui (console user interface).


The initial root password is not set (empty). When asked for the password, simply confirm with “Enter”.
To configure grommunio, please proceed as follows:

  1. Set a self-defined root password.
  2. Set an IP address, a host name and DNS server. If you are using DHCP (e.g. for test purposes – it is at least recommended to use static DHCP reservations because of the DNS entries), this part can be skipped.
  3. After this basic configuration has been carried out, grommunio-setup can be executed to take over the last steps.
  4. To start grommunio-setup, please use either the grommunio cui or any other terminal of the appliance.


SSH is activated by default, so grommunio-setup can also be carried out via remote SSH.
Finally start grommunio-setup as user root and follow the instructions of the interactively requested information.


For smooth operation, the grommunio appliance opens various ports so that clients can access it. Please note that the following ports are open by default:

  • 25 (smtp)
  • 80 (http)
  • 110 (pop3)
  • 143 (imap)
  • 993 (imaps)
  • 995 (pop3s)
  • 8080 (admin)

Download the grommunio appliance

Please choose a platform

Please note: The ISO image is a CD / USB hybrid installation medium for x86_64, which can also be transferred to a USB stick using USB imaging tools such as

Please refer to the documentation for more information

Download the desktop app

grommunio Logo

Desktop App

grommunio Logo

Desktop App

grommunio Logo

Desktop App

Please note: The desktop app works with a grommunio server only.

Download the mobile apps

grommunio Logo


grommunio Chat on the App Store
grommunio Chat on Google Play
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grommunio Meet on the App Store
grommunio Meet on Google Play

Please note: The mobile apps work with a grommunio server only.