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Common Access Card help for your

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Secure / Multipurpose Internet Mail Extensions (S/MIME) is a standard for public key encryption and signing of MIME data


For users of the email system, please follow guidance here to set up your Internet Explorer web browser. 


Air Force Users, please follow this guide

NOTE:  This information was derived by following information here.



Windows Installation Steps
Step 1: Obtain a CAC Reader
Step 2: CAC Reader driver
Step 3: DoD Certificates
Step 4: ActivClient (Optional)


Utilizing the Edge web browser, download the S/MIME extension from this link:


When you see this message at the bottom of your screen, click Save as to save to your downloads or desktop folder



Navigate to your downloads folder (or where you saved it to), and double click it



When you see this screen, double click the Install (button)




Once you see this screen you know it is installed:



You will now need to edit your registry to allow the S/MIME to function properly


Manual method:

Navigate to HKEY Local Machine -> SOFTWARE -> Microsoft -> Windows ->CurrentVersion -> Right click on: AppModeUnlock, select New DWORD (32-bit) Value Enter:  AllowAllTrustedApps hit <enter>, then right click and modify the value to: 1



HKEY_LOCAL_MACHINE ->SOFTWARE ->Microsoft ->Windows -> CurrentVersion -> Right click on: AppModeUnlock, select New DWORD (32-bit) Value Enter: AllowDevelopmentWithoutDevLicense hit <enter>, then right click and validate the value is 0


Automated method:

Edge registry setting

Chrome registry setting



From the Edge browser click the 3 little dots (elipse) in the top right corner of the web browser





Select Extensions from the drop down menu







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Last Update or Review:  Tuesday, 12 January 2021 10:02 hrs

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