Private Key - Uwe Gradenegger

Microsoft Outlook: Emails encrypted with S/MIME cannot be opened. The error message "Your digital ID name cannot be found by the underlying security system" appears.

Assume the following scenario:

A user receives an e-mail message encrypted with Secure/Multipurpose Internet Mail Extensions (S/MIME).
The message cannot be opened.
When opening the message, the following error message is displayed:

Sorry, we're having trouble opening this item. This could be temporary, but if you see it again you might want to restart Outlook. Your digital ID name cannot be found by the underlying security system.

Requesting a certificate fails with the error message "The requested operation cannot be completed. The computer must be trusted for delegation and the current user account must be configured to allow delegation. 0x80090345 (-2146892987 SEC_E_DELEGATION_REQUIRED).". When importing PFX files, the private key is missing.

Here's the scenario:

The import of a PFX file seems to be successful, but afterwards the private key is missing. A check with certutil ends with the error message "Missing stored keyset".
Requesting a certificate on a client fails with the following error message:

The requested operation cannot be completed. The computer must be trusted for delegation and the current user account must be configured to allow delegation. 0x80090345 (-2146892987 SEC_E_DELEGATION_REQUIRED).

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