E-mail Thunderbird? Sending is not possible?

Menu bar where SEND is, 3 button, stands with me: activate protection, on the laptop is: the image with the padlock and the letters S / MIME and here is the sending, how can I do that on the PC Delete and restore the S / MIME

Unfortunately, it is not clear what you want. Send? Or put something away?

Please post screenshots and what settings you have set. Do not forget to overwrite personal entries with x.

I suspect that if I can do away with the sending is synonymous, because I've tried how it works with Encrypted with Enigmail but I did not fit and since the send is no longer, at the bottom left of the page is green p-p Privacy protection: Unbekant