Email Encryption

Hi,

I am trying to exchange encrypted emails between my friends Mac and my iPad however when I try to do so my Mail app (on my iPad) accepts the email encryption certificate and it associates it with my friends email address however when I go to reply to the encrypted email, Mail doesn’t allow me to add encryption when I go to reply. How would I add encryption to my reply and to any emails going from my iPad?

Any help would be appreciated,

Thanks