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.

    /localmutex

   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:user@example.org?subject=hello&body=bodytext"

    /open PATH

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

    /newmail

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

    /newcontact

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

    /newevent

    This parameter will open a window to plan an event.

    /newtask

    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

    /activate

    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.

    /deactivate

    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

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).

Windows

• Windows 10 or higher - systems with up-to-date security from Microsoft are recommended, but with some tweaks (like manually enabling TLS 1.2 Win 7) eM Client can still be used on older systems, it is not blocked from our side, but we cannot guarantee it
• 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.

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

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

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

2.        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

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.

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.

For example:

<settings>
<restrictions>
<ChatRestriction><AllowedHostRegExp>emclient.com</AllowedHostRegExp></ChatRestriction>
<AccountCountRestriction><AccountCount>1</AccountCount></AccountCountRestriction>
</restrictions>
</settings>

For a complete list of restrictions contact our support department at info@emclient.com.

   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.

XEP-0004
XEP-0030
XEP-0047
XEP-0054
XEP-0065
XEP-0066
XEP-0077
XEP-0085
XEP-0092
XEP-0231
XEP-0280
XEP-0313
XEP-0363

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