View certificates

Do one of the following:

In the main Microsoft Outlook window, on the Tools menu, click Options, and then click Security.
Click Settings.
Under Certificates and Algorithms, click Choose.
Click the certificate you want, and then click View Certificate.

In the message, click Signed or Encrypted on the Signed by line.
Click Details.
Click Signer Layer or Encryption Layer, and then click View Details. A dialog box is displayed with general information about the certificate.
To see details about the certificate, click View Certificate.