Preparing for installation

There are a few steps we recommend that you take in preparation of the product installation:

After purchasing ESET Mail Security, download .msi installation package from ESET’s website exlink.

Make sure that the server on which you plan to install ESET Mail Security meets system requirements.

Log on to the server using an Administrator account.


Execute the installer using the Built-in Administrator account or a domain Administrator account (in the event that local Administrator account is disabled). Any other user, despite being a member of Administrators group, will not have sufficient access rights. Therefore you need to use the Built-in Administrator account, as you will not be able to successfully complete installation under any other user account than local or domain Administrator.

If you are going to do an upgrade from an existing installation of ESET Mail Security, we recommend that you backup its current configuration using the Export settings feature.

Remove /uninstall any third-party antivirus software from your system, if applicable. We recommend that you use the ESET AV Remover exlink. For a list of third-party antivirus software that can be removed using ESET AV Remover, see this KB article exlink.

If you are installing ESET Mail Security on Windows Server 2016, Microsoft recommends exlink to uninstall exlink Windows Defender Features and withdraw from Windows Defender ATP enrollment to prevent problems caused by having multiple antivirus products installed on a machine.

If you are installing ESET Mail Security on Windows Server 2019, Microsoft recommends exlink putting Windows Defender into the passive mode to prevent problems caused by having multiple antivirus products installed on a machine.


If Windows Defender Features are present on your Windows Server 2016 or 2019 during installation of ESET Mail Security, these features are turned off by ESET Mail Security to prevent collisions of real-time protection between multiple antivirus products. Also, Windows Defender Features are turned off by ESET Mail Security with every system start-up / restart.

There is an exception to this — if you are doing a component installation without Real-time file system protection component, Windows Defender Features on Windows Server 2016 are not being turned off.

For comprehensive view, see matrix of ESET Mail Security features and Microsoft Exchange Server versions and their roles.

You can check the number of mailboxes by running the Mailbox Count tool, see our Knowledgebase article exlink for details. Once your ESET Mail Security is installed, it will display current mailbox count at the bottom of the Monitoring window.


You can run ESET Mail Security installer in two installation modes:

Graphical user interface (GUI)
This is the recommended installation type in a from of an Installation Wizard.

Silent / Unattended installation
In addition to the Installation Wizard, you can choose to install ESET Mail Security silently via command line.


We highly recommend installing ESET Mail Security on a freshly installed and configured OS, if possible. If you do need to install it on an existing system, we recommend that you uninstall previous version of ESET Mail Security, restart the server and install the new ESET Mail Security afterwards.

Upgrading to a newer version
If you are using an older version of ESET Mail Security, you can choose suitable upgrade method.


After you've successfully installed or upgraded your ESET Mail Security, further activities are:

Product activation
Availability of a specific activation scenario in the activation window may vary depending on the country, as well as the means of distribution.

Post-installation tasks
See the list of recommended tasks you can perform after a successful installation of ESET Mail Security.

Configuring server protection
You can fine-tune your ESET Mail Security by modifying advanced settings of each of its features to suite on your needs.