Using Opera on an iMac running High Sierra.
When I go to a newspaper article and click on Opera's share icon, then mouse down to Mail, it opens a new email in Apple's Mail.app with only the URL of the article.
When I do the same thing in Safari, it opens a new email in Apple's Mail.app with the entire text of the article including photos.
That would be a wonderful feature to have because: when you send full articles, there is no danger that the person to whom you are sending them will eventually reach the limit of X free articles per month posed by some sites with a paywall.
Otherwise, just loving Opera and have made it my default browser.