Outlook unblock “unsafe” attachments

Regedit, find: Outlook 2007 [HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Security] Outlook 2010 [HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security] Outlook 2013 [HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Security] Outlook 2016, Outlook 2019 and Office 365 [HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Security] Level1Remove string Value .cer;.exe;.xxx for the stuff you want to unblock.