Is it possible to send an encrypted email to two people? I can send individual encrypted/signed emails fine, but if I CC someone, it will not allow it? Is this a limitation of the software or am I doing something wrong?
There are no limitations.
You do however need the Public Key of the person you are trying to send to.
And you must have an entry for them in your address book so that the client
knows which certificate to use for that email address.