That's strange, I think it should always be included in a new installation. If you are using the search box above the list, do you have any better luck if you just type ma instead of mailto?

If you have been running Firefox for a while, it's possible that the file which stores your Application preferences might have become corrupted. Because the file is difficult to edit, we generally suggest removing/renaming the file and having Firefox generate a fresh one. Here's how:

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button. This should launch a separate window listing various files and folders.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

Pause while Firefox finishes its cleanup, then rename mimeTypes.rdf to something like mimeTypes.old

Start Firefox back up again. Does mailto return?

That worked perfectly. Thanks so much.