Frequently Asked Questions

For Admins

We’ve prepared answers to a couple of the most frequently asked questions that should help you get started. We hope that you can find your answer here, but if not, please let us know through the Community Support or the VIP Support (if you’re a Pro license user). We will be happy to answer any questions you may have!


  • Can I apply startup parameters to eM Client?

    Yes, you can definitely use a number of startup parameters.

    Here is a short overview:

        /dblocation PATH

        This parameter will determine which folder will eM Client load the main database from. If the given folder does not exist, eM Client will create the folder and a new, empty database in it. Without this parameter, eM Client will load the database from the currently set default location.


       Use this parameter when deploying the application in a Remote Desktop Services or Terminal Services environment where accessing global mutexes (short for „mutual exceptions“ in programming) is forbidden – the application will use local ones instead.

        /mailurl RECIPIENT

        Use this parameter to create a new message with a pre-defined email address compliant with RFC 6068.
    Example: MailClient.exe /mailurl "mailto:[email protected]?subject=hello&body=bodytext"

        /open PATH

        With this parameter you can open any .eml, .msg, .vcf, or .ics file in eM Client.


        This parameter will open a window to compose a new mail.


        This parameter will open a window to create a new contact.


        This parameter will open a window to plan an event.


        This parameter will open a window to create a new task.

        /importsettings PATH [-s] [-p PASS]

        This parameter defines a file which contains eM Client settings and its password, which needs to be used to import the data. It needs to be an .XML file and can contain application settings, account configuration, templates, quicktexts, and rules. PATH is the location of the file. The rest of the parameter options are optional. [-s] stands for "silent" and means that the settings will be imported without opening the UI. [-p PASS] is for inserting the password, if there is one protecting the file.
    Example: MailClient.exe /importsettings "c:\Temp\settings.xml" -s -p MyPassword


        You can easily activate your eM Client using this parameter and activation key.

        This parameter can also be used without the Activation key, but for activation to be possible in this case eM Client needs to have a LastActivationKey entry in its database with a valid Activation key. Usually, the LastActivationKey value is set using the /importsettings parameter.


        This parameter will deactivate the license in your device. This can be useful when you have a set number of seats on your license and want to quickly free up the space by deactivating the device you no longer plan to use.

    Note: This answer applies only to Windows version.

    Read more in the Documentation: Startup Parameters

  • What size capacity does eM Client have?

    eM Client does not enforce any size limits on your database or on your accounts.

    The database size is technically limited by the free space on your disk, where the database is saved (default is set to C).

    Your email account size can be limited by the space on your email server if you use an email protocol which synchronizes your data with it (IMAP or EWS).

  • Minimum system requirements

    In general, the system requirements will be dependent on the current version of .NET used in eM Client. At this time, it is .NET 6.


    • Windows 7 or higher - systems with up-to-date security from Microsoft are recommended, but with some tweaks (like manually enabling TLS 1.2) eM Client can still be used on older systems
    • 350 MB of free space for installation.
      • You will need additional space for data, which can be stored on a different drive if needed! Since eM Client has no limit on the number of emails/data stored in its database the only limitation is the capacity of the hard drive installed in your PC. Shared folders or network drives are not recommended due to potential database conflicts.
    • Minimum of 2 GB of RAM and 1.6 GHz CPU
    • Recommended for memory and processor - the more GB and GHz you have, the better :]

    Terminal servers

    eM Client can, of course, be used in a Terminal server environment as well. Windows Server 2012 and newer Windows server versions are supported.

    Mac OS

    We officially support only the last three macOS versions (but some older versions, such as eM Client 8, can still run on El Capitan too).

  • Installation of eM Client

    eM Client is distributed as a standard MSI package so you can use standard MSI parameters. You'll probably want to use /quiet or /qn for silent installation. All the MSIEXEC parameters should be supported though!

    eM Client has three custom paramaters if you need a silent install:


    All versions of eM Client can be found in our Release history.

  • Deployment of eM Client

    There are two different ways to deploy eM Client and activate the license automatically:

    1.        Deployment via Command Prompt

    If the goal is to simply install eM Client and load the license, use the following command in Command Prompt: MailClient.exe /activate {insert activation key here}

    Similarly, you can easily deactivate eM Client license by using: MailClient.exe /deactivate

    1.        Automatic deployment

    If a bit more complex setup is required, you can use our "Automatic deployment process" which allows you to push various sets of settings along with the license key too. Find more detailed instructions here

    Read more in our blogs: eM Client Server Settings & Advanced Startup

  • eM Client setup and migration

    Autodiscover is supported in eM Client so you should be able to set up all accounts easily.

    OAuth for Google accounts and Exchange is supported as well.
    OAuth for Google is fully automatic.
    OAuth for Exchange is automatic in eM Client 8.2, for older versions please follow these instructions.

    In case you need to set up an account manually, choose Mail > Other in the account setup window.

  • eM Client's License manager

    The License Manager allows you to manage all your licenses and their activations from one place.

    By manage, we mean that you can activate/deactivate them and also push various settings centrally.

    Watch our video tutorial or read the Licensing guide for more detailed instructions.

    It is not possible to connect to the License manager via TLS 1.0 and 1.1, you need at least TLS 1.2 to be able to connect to the License manager.

  • eM Client Restrictions

    In case you need to limit certain functionalities in eM Client (restrain your users from using personal chat accounts or limit the number of email accounts they’re allowed to use) use the Server settings feature in License manager to push custom restrictions that limit eM Client’s capabilities.

    For example:


    For a complete list of restrictions contact our support department at [email protected].

  • How does Autodiscover work?

    When eM Client uses its Automatic setup for email accounts, it uses your mail server's Autodiscover settings to get the correct settings for all available services for your email account.
    But it also checks some other details before, and even after if no autodiscover file is found.

    The order in which eM Client check for these settings is as follows:

       1. Registry check - first eM Client checks your system registry to see if you have any overrides set for your account - if so, these settings are used.

       2. Service Connection Points (SCPs) or Active Directory for on-premise - some services publish information about their existence by creating SCPs, which client application can use for connection.

       3. SRV records in Domain Name System (DNS) - these identify computers hosting specific services and their ports, which are then used for the account setup.

       4. Office 365 - check if the domain and email are stored on a paid Microsoft 365 server, then use Office 365 setup (Exchange).

       5. Guess autodiscover address based on the domain name (https://your-domain/autodiscover/autodiscover.xml, https://autodiscover.your-domain/..., ...)

       6. Guess IMAP/POP and SMTP settings - try standard/common host names and port number until the mail server responds.

    If all of these fail the program will ask you to use manual setup instead under Mail > Other.

  • Which XMPP specifications are supported?

    We support


    and a proprietary XEP between eM Client and IceWarp services for file sharing