Overview
The preferred Microsoft Message Encryption functionality does not rely on local client certificates. If you attempt to send an email message, and see an Invalid Certificate error, it may be attempting to encrypt the message using local S/MIME settings and certificates.
Invalid Certificate
Microsoft Outlook cannot sign or encrypt this message because there are no certificates which can be used to send from this email address 'jvandal@uidaho.edu'. Either get a new digital ID to use with this account, or use the Accounts button to send the message using an account that you have certificates for.
Try to send the encrypted email using Outlook for the Web at https://mail.uidaho.edu/.
In Outlook, go to the top left File menu and then click on the bottom right "Options".
Click on Trust Center and then Trust Center Settings...
Select "Email Security" and verify the options to encrypt and sign are UNCHECKED. Click OK to exit through all of the dialogs.
Try sending the encrypted email again using the instructions here: https://support.uidaho.edu/TDClient/40/Portal/KB/ArticleDet?ID=1618