Problem: Outlook shows an ActiveX warning when loading the Add-In.

Solution: Add the fully qualified domain name (FQDN) of the MailStore Servers computer to the Local intranet sites in the Internet Options of the Internet Explorer. Occasionally it is not sufficient to add the entire domain, you have to add the FQDN of the MailStore Server explicitly. This can also be done using group policies.

In case adding the FQDN is not sufficient, also check whether in Internet Properties > Security > Trusted sites > Custom level... > ActiveX controls and plug-ins the option Initialize and script ActiveX controls not marked as safe for scripting is not set to Prompt and change it to Enable or Disable if necessary.

Article-ID: KB20150325-0-EN (Deutsche Version)