Product eM Client for AppSuite FAQ

What is eM Client?

The eM Client is a full-featured email client with a modern, familiar and easy to use interface that also provides offline capabilities. Windows users – the primary target for this offline email clients - will appreciate this client that also provides calendar, tasks and contacts features.

Which OX App Suite features are available with eM Client?


  • Secure communication (SSL / TLS)
  • Advanced email rules management
  • Spell-check across the application
  • Templates, signatures, tags and categorizations


  • Various calendar views
  • Share calendars and tasks with other people
  • Full text search in events and tasks
  • Schedule meetings using free / busy


  • Custom contact views
  • Exhaustive number of data fields
  • Categorization and folders support
  • Easy contacts merging
  • Communication history

Can I rebrand eM Client?

Yes. If you imagine that OX App Suite is your face to the customer using your logo and corporate design, eM Client is one more touch point. Because it is branded with your logo and design, even on their local machines users do not leave your environment.

What are my benefits from switching to eM Client?

Using your branded version of eM Client is your chance to increase loyalty with your customers and reduce the likelihood of users leaving your ecosystem – while providing an enhanced user experience and offering features to your users which so far have been only available through our web application.

Who has developed eM Client?

eM Client for OX App Suite is developed by the Open-Xchange partner eM Client. We are partnering closely with eM Client – you will be selling an official Open-Xchange product.

Can I preview eM Client?

Please get in touch with your Sales representative if you are interested in a demo, preview or test account of eM Client for OX App Suite.

Where can I find installation, configuration, update and requirements information?

You will find the requirements under eM Client for OX App Suite and Platform Requirements

Pricing and Availability

eM Client for OX App Suite is part of a standard OX App Suite from Open-Xchange and its partners. The tool is available for all customers who have a valid Open-Xchange license. Please contact Open-Xchange Sales for further information and pricing details.

Known Limitations

Please consider the following known limitations for all 6.x versions of eM Client for OX App Suite:

The correct set up is mandatory:

(This is also an explanation for the data fields in the XML file (provider.xml) and the description, why eM Client for some customers does no longer work after 14 days)

The eM Client for OX App Suite does not require a license key, but does make a capability check as described in this article. A capability check is executed against the App Suite Server. Unfortunately the 6.x versions of eM Client for OX App Suite do not have a UI field to set or change the URL of that Server.

For that reason, we use a little trick in that version and set that URL by using the respective piece from XML snipped we ask for in the "Autodiscovery" section of that article.

The following describe the steps during the user onboarding and what happens at the client:

1. End user downloads eM Client for OX App Suite and starts the installation

2. The program starts with the configuration dialog. The End User has to enter her/his Mail address.

3. eM Client for OX App Suite will do a MX Lookup of that domain and tries to match that with the "DNS" entry in the provider.xml

4a. If it does find a match, it will configure eM Client for OX App Suite with the respective settings (URLs, ports...). In this case the App Suite URL will be set and a capability check as mentioned above is possible. The client is fully functional.

4b. If it does not find a match, eM Client will try standard settings for the server identified by the MX Lookup. Most of the time this will lead to a result that seems "successful", but as the App Suite URL can not be set correctly in this case, it will result in a non functional client after 14 days, because a capability check is not possible. In most cases there is not any or an incorrect entry in the provider.xml for the users mail address. In this case the user can manually change any entry in the provider.xml in the respective emclient directory to the correct settings. After that the user needs to re-run the account setup in eM Client for OX App Suite.

Unfortunately for most end users it is difficult to realize if the setup was really successful, so they will only complain after 14 days with their provider. As a provider / admin you should send in the information form from "Autodiscovery for partners and customers" and wait for an update before rolling out the client to a larger group of users.

Login / Mailaddress / Password

eM Client for OX App Suite is using the mail address as the starting point. In setups where the login is completely independent from that mail address, the onboarding of eM Client for OX App Suite unfortunately is not straight forward and may lead to unexpected error messages. The user may need to manually change the settings in the account section of the client.

Distribution lists

Distribution lists are not supported in that version. Compare:

Sieve Filter rules

A synchronization of Sieve filter rules is not supported in the 6.x versions of eM Client for OX App Suite