username@local Outlook 2007 Exchange 2007

I am needing some help with sending an encrypted email.

I have the public key for the person that I am trying to send the email to. I select encrypt email. I click send.

Then i get the “Select Certificates For ”

I select Openpgp and it fills out the person I am trying to sends certificate.

But for mine (username@local) i select, click ok and click send and it opens the “Select Certificates For ”

Any Ideas on how to fix this?

I am able to get encrypted messages and decrypt them.