I am not sure how this happened, but my Mac is showing Opera browser to use whenever I click an email link in the browser rather than Mac Mail (in the Share extensions). So, when I click a "mailto" link in the browser, it goes to my ISP provider's webmail page.
How do I change this back to Mac Mail?
Open Mac Mail and set that as your default?
Duh! Okay, I feel dumb. Of course, that's it! Thanks!