The problem:
Recently Microsoft has removed this option for security reasons with this update: May 2, 2017, update for Outlook 2016 (KB3191883) but luckily we can restore it with a simple registry hack. Before this update we can create a new Rule for the inbox mail in which specify that if a mail meets certain criteria (sender, subject, …) than Outlook can start an application on our computer (simple, without parameters, I think….).
Important
Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.
- Exit all Microsoft Office applications.
- Start Registry Editor. To do this, use the appropriate method for your version of Windows.
- In Windows 10, go to Start, enter regedit in the Search box, and then select regedit.exe in the search results.
- In Windows 8 or Windows 8.1, move your mouse to the upper-right corner, select Search, enter regedit in the search text box, and then select regedit.exe in the search results.
- In Windows 7, select Start, enter regedit in the Start Search box, and then select regedit.exe in the search results.
- Locate and then select one of the following registry subkey:
Outlook 2016:
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Security\
Outlook 2013:
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Security\ - On the Edit menu, point to New, and then select DWORD Value.
- Enter EnableUnsafeClientMailRules, and then press Enter.
- In the Details pane, press and hold (or right-click) EnableUnsafeClientMailRules, and then select Modify.
- In the Value data box, enter a value, and then select OK.
Note If you set the value to 1, the rule actions are enabled. If you set the value to 0, the rule actions are disabled. - Exit Registry Editor.