Search MilitaryCAC:

Site Map logo

.com | .us | .ml  | .mobi | .net | .org

The Definitive Source for Everything CAC

Common Access Card help for your

Personal Computer



Make a Donation button image



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


For users of the Army365 system, please follow guidance here to set up your Microsoft Edge web browser


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


For others, please know I got this to work once, but never again.


Air Force Users, please follow this guide

NOTE:  This information was derived from information that used to be here. Now removed



Windows Installation Steps
Step 1: Obtain a CAC Reader
Step 2: CAC Reader driver
Step 3: DoD Certificates


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



This is where I ran into a road block and could not get it to work.




If you have questions or suggestions for this site, contact Michael J. Danberry



ACRONYM Reference Page


GoDaddy Site Certified seal


Make a Donation button image


Last Update or Review:  Thursday, 19 May 2022 18:49 hrs

The following domain names all resolve to the same website:,,, &