Hello,
The default Command-Shift-D key combo for “Send” in Apple Mail has stopped working for me on one of my computers. I’ve checked every standard source of key combos that might be competing with it; as well, I’m a Keyboard Maestro user, and I have no competing macros.
My workaround is a Macro in Keyboard Maestro that uses the same Command-Shift-D key combo, but I’d dearly love to figure out this puzzle. For what it’s worth, I’ve examined the Console, and I see no messages when I press the combo.
Edit: I should add that I don’t get an error beep when I use the combo in Apple Mail.
Since you don’t mention trying them, the obvious next steps are close and reopen mail; then log out of your account and then log back in; then try a restart of the computer (though I suppose that could just be step two). See if those fix the problem.
Could Apple have changed the keystroke? If the other computers are using a different version of Mail, then that may be a possibility.
Can you check to see if the app reports a different keystroke? Look at menu-bar items and for tool-tips on any buttons. (I don’t use Mail, so the previous advice is, unfortunately, vaguer than I’d prefer.)
I had tried restarting, but to no avail. And the app still shows Command-Shift-D as the assigned keystroke. I’m also using Apple Mail on my other computer, and it seems to work fine.
Sounds like you’ve installed (or updated) something that’s intercepting the keystroke for its own purpose. Perhaps a launcher, or screenshot utility, or some other always-on app.