Troubleshooting MS Outlook S/MIME Issues
STEP 1
Go to Outlook, Click:
File
Options
Trust Center
Trust Center Settings
Email Security
Next to the settings button should be the cert title, Close Outlook and go to step 2.
If it is blank and you click settings and you are able to choose a cert using the Choose button then do it and hit ok.
Exchanging emails with DOD use: ORC
STEP 2
Please try these steps:
Go to Internet Explorer:
Tools
Internet Options
Content
Certificates
Personal
Advanced
Check boxes: Client Authentication & Secure Email
Hit OK, Close all windows.
STEP 3
Click Start
Type MMC (in the search programs and files bar)
Enter
Hit Ctrl + M
Double click Certificates
My User Account
Ok
Certificates – Current User
Other People
Certificates
Delete problem senders certificates
Close – Save console settings to Console1 yes.
Step 4
Go to Outlook
Delete the contact
Have contact send Signed email
Right click reply senders name
Add to contacts
Click Certificates
Select Cert
Properties
Trust
Explicitly Trust this Certificate
Hit ok, Save & Close.
Have contact send Encrypted email
Right click reply senders name
Add to contacts
Update
Save & Close contact
STEP 5
Download and install the latest version of Install Root ) Militarycac *.MSI version, there is a Non admin version which works great for domain environments.
Once installed Right click and subscribe to ECA root, then install certificates and save settings. This will add and correct any cert chain issues.