No email encryption option in Mac OS 10.14

Hello

So finally got my email certificates installed.
I have 2 emails set up and each has its own certificate. testing it out. I’m trying to email myself from one email address to the other. I can sign the emails but the lock button is greyed out. google hasn’t helped so far.
I got this to work with outlook. it sends encrypted and signed emails but can’t get it to work with apple mail.

I’m running Mac OS 10.14 and using Apple mail.

Thanks.

Ok. so I thought the encryption should work if I email myself. since I have a certificate for each of the 2 email address that I’m using. but I guess that’s not the case. at least with apple mail.
I also have a certificate installed in my wife’s computer profile for her email account. and when sending her an email . the encryption works both ways. from me to her and from her to me.
Now to figure out the iOS issue… in another post.

Thanks.