I use both OpenPGP and S/MIME in my Apple Mail, but by default all new Messages are sent using OpenPGP. It’s easy to change this behaviour in the Terminal:
Set S/MIME as default security method
defaults write org.gpgtools.gpgmail DefaultSecurityMethod -int 2
Use OpenPGP as the default again:
defaults write org.gpgtools.gpgmail DefaultSecurityMethod -int 1Got this from https://gpgtools.tenderapp.com/kb/gpgmail-faq/gpgmail-2-hidden-settings#define-the-default-security-method-to-be-used
Great tip, still works in macOS Monterey. Thank you!