Send Mail Action stopped working

The 'Send Mail Action' with 'and send now' has stopped working.
Is anyone else experiencing this?
I did just migrate to a new computer this week, but I am not getting any privilege prompts or the like. I believe they are all set accordingly.

I tried this and it appears to work fine for me. I would try the usual trouble shooting steps for something like this, starting with relaunching Mail and maybe restarting your Mac.