Sorry, Firefox has never had a feature to capture an image or copy of a webpage and then interface with your email client or webmail to send that image or copy.

Over the years there have been a few different extensions available that would add that type of feature to Firefox. Try using this extension: https://addons.mozilla.org/en-US/firefox/addon/fireshot/

I've installed, but not yet tried this addon, so I'm not quite sure it will capture the entire page, not just a screen's worth.

But even if it does, it seems like a more involved process than simply saying "mail this"--a nuisance if you do this as often as I do.

As you said, there have been extensions that did what I want, but a general rule is that any Firefox addon that I really really use a lot will be made invalid by the next Firefox update or the one after that. At least, the addons that used to work at sending pages still sorta work, sending not pages but their URLs.

edit format {leading space removed. J99

Note that Firefox has a setting in the web developer toolbox settings to add a button to the toolbar of the Web Developer toolbox to take a full page screenshot.

• https://developer.mozilla.org/Tools/Tools_Toolbox#Settings
• Available Toolbox Buttons: Take a fullpage screenshot

The (default) file name is "Screen Shot yyyy-mm-dd at HH.MM.SS.png" and the file is saved to the Downloads folder. You can right-click and select "Inspect Element" to open the Inspector (Firefox/Tools > Web Developer) and have access to the developer tools including the cogwheel icon to access the toolbox settings and find the "Take a fullpage screenshot" (camera) button once you have enabled this button.