The Outlook Add-in is not visible
Posted by Daniel Weuthen on 18 Mar 2019 14:10

Problem: Although the installation of MailStore's Outlook Add-in was successful, it is not displayed in Outlook.

Solution: This can happen due to various reasons:

  • Check whether the MailStore Outlook Add-In is listed in Outlook OptionsAdd-Ins. In case the Add-In is not listed, click Manage > COM Add-Ins > Go and verify that the Add-In entry is checked. Is the Add-In not listed in COM Add-Ins navigate to Outlook OptionsAdd-Ins > Manage > Disabled Items > Go and ensure the Add-In is Enabled. Afterwards verify that the Add-In entry is checked in COM Add-Ins. If the Add-In is not listed in COM Add-Ins and in Disabled Items open Outlook as an administrator, navigate to Outlook Options > Add-Ins > Manage > COM Add-Ins > Go > Add... naviate to the instalaltion directory of the Add-In and add the file MailStoreOutlookAddin3_x64.dll or MailStoreOutlookAddin3_x86.dll, depending on the bittness of your Outlook installation. You may have to re-install the Add-In so the DLL files will be registered.

  • The load behavior of the Outlook Add-In is controlled by registry keys. When using a 64-bit Office or a 32-bit Office on a 32-bit Windows the value of the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ Outlook\Addins\MailStoreOutlookAddin3.AddinModule\LoadBehavior has to be 3. When using a 32-bit Office on a 64-bit Windows the key can be found in the path HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Office\ Outlook\Addins\MailStoreOutlookAddin3.AddinModule\LoadBehavior. In case these keys exit in HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\ Outlook\Addins\MailStoreOutlookAddin3.AddinModule\LoadBehavior, the keys in HKEY_LOCAL_MACHINE still will be preferred and have to be adjusted there.

  • Check whether the MailStore Outlook Add-In is listed in Outlook Options > Add-Ins > Manage >COM Add-Ins > Go and Load Behavior is either "Not loaded. Certificate of signed and load at startup COM Add-in is not in trusted source list." or "Not loaded. The user selected to disable macros.". In this case the user has  set not set the setting Outlook Options > Trust Center > Trust Center Settings... > Macro Settings and has set Apply macro security settings to installed add-ins and has disabled the Add-In during the start of Outlook. To load the Add-In lower the macro security and enable the Add-In during the start of Outlook or disable the setting Apply macro security settings to installed add-ins.

  • By default the Add-In integrates into the Outlook Ribbon as main tab. Navigate to Outlook Options > Customize Ribbon > and verify that there is a MailStore entry in Main Tabs. In case, there isn't, you can add the Add-In with Choose commands from > Main Tabs > MailStore > Add or Customizations > Reset. You are free to adjust the Add-In according to your needs here.

  • Another reason is a corrupt Outlook profile. Try to create a new profile and see if the MailStore Outlook Add-in is displayed there.

  • Check whether the .NET framework 4.5.1 is installed or enabled as a feature. For example, this is not the case with Windows 7 by default.

  • Ensure you do not have disabled the MailStore Group Policy "Enable MailStore Outlook Add-In Toolbar by default".

  • The MailStore Outlook add-in might have been disabled by Outlook, e.g. due to excessive loading times, in this case please read this article:

Article-ID: KB20121128-1-EN (Deutsche Version)

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