Problem Installing An Email Certificate In Outlook 2013? Try This Fix.

To protect my email from snoops and spooks, I wanted to setup an email certificate for signing and encrypted my messages. I use Outlook 2013, and signed up for a free Comodo email signing certificate.  Using Firefox browser, I installed the certificate.  I then went into Outlook 2013, but was unable to sign my messages. Outlook kept showing me an Invalid Certificate message. It read, "Microsoft Outlook cannot sign or encrypt this message because there are no certificates which can be used to send from the e-mail address .  like this:

Invalid Certificate Message

 The way I solved this problem was first to revoke the certificate that had been assigned to me. Next, I started the process again, this time using Internet Explorer.  So I started IE, and then went to Comodo and signed up for the certificate, and then I claimed and installed the certificate using Internet Explorer.

When I went into Outlook 2013 and signed a message, everything worked!

I don't know why this works, it just does. Perhaps Firefox uses a different location to store these certificates and it freaks Outlook.  Give it a try and let me know if this works for you.