It was here: https://www.dmdc.osd.mil/ump/umphome.htm, but that just gives a 404 now.
The new site is here: https://www.dmdc.osd.mil/self_service/
From the site you can:
- Add/Change email address to receive initial or new Email Signature and Email Encryption Certificates
- Add Personnel Category Code to the User Principle Name of the Email Signature Certificate
- Activate the PIV Authentication Certificate
- Download applications
- View/Update contact information