Additional information In troubleshooting mode, the icon returns as normal. Yahoo mail in Crome browser, with all extensions active works OK and the send icon is shown as normal.

I have deleted all extensions and in Firefox, I cannot see the send icon in Yahoo mail

If all extensions are removed but the **Yahoo Send icon** is still missing in Firefox, try the following steps:

1. **Clear Firefox Cache**

  Go to Settings → Privacy & Security → Clear Data.

2. **Check Yahoo Mail in Another Browser**

  See if the Send icon appears in Chrome or Edge to confirm it's a Firefox-specific issue.

3. **Switch to Standard Mode**

  Go to Settings → Privacy & Security → make sure you're not in Strict Tracking Protection mode, which can break some site features.

4. **Disable Enhanced Protection for Yahoo**

  While on Yahoo Mail, click the shield icon in the address bar → Turn off Enhanced Tracking Protection.

5. **Refresh Firefox**

  If the issue remains, try "Refresh Firefox" from the Troubleshooting section in Settings.

Thanks for the suggestions.

As said, Yahoo mail worked normally, showing the send icon in a Crome browser.

Some hours later I went back to Firefox and Yahoo mail and to my surprise the Send icon had re-appeared.

I have re-installed all the extensions deleted previously and again, to my surprise, the Send icon is showing normally.

It remains a mystery, but I'm glad all is good again! Yhanks again for your input.