Thanks for you reply, Dropa. I use btinternet.com for my emails. When composing an email, the page does not shift up or down and the ""Send" & "Dismiss" buttons are not visible. I had a long session with their BTSupport before contacting Mozilla Support. BT suggested the problem may have been caused by something (not specified) to do with Firefox. I also use icloud email and have not had any problem sending on it.

I used MS Edge  to log into btemail and sent a test email, which was received. I did notice that only half ofBT's  blue SENT and DISCARD buttons were displayed at bottom of page. I was just able to click on SENT

A copy of that email sent 5 mins earlier on the Firefox BT page did not arrive. The SENT and DISCARD were not displayed. I hope you can follow this complicated matter.

worked on first of three tries in Firefox private mode. I will get back to btinternet. Thank you.

To reinstall Firefox on your Windows 11 computer, follow these steps:

Open the Start menu and search for "Apps & Features". Click on "Apps & Features" in the search results. Scroll down and find "Mozilla Firefox" in the list of apps and click on it. Click on the "Uninstall" button and follow the prompts to uninstall Firefox from your computer. After the uninstallation process is complete, go to the official Mozilla Firefox download page (https://www.mozilla.org/en-US/firefox/new/) and download the latest version of Firefox for Windows. Once the download is complete, run the Firefox installer and follow the prompts to install Firefox on your computer. Note: Before you uninstall Firefox, make sure to back up your bookmarks and any other important data. You can export your bookmarks by clicking on the "Library" button (the icon that looks like a book) in Firefox, selecting "Bookmarks" and then "Show All Bookmarks". In the Library window, click on "Import and Backup" and select "Export Bookmarks to HTML". Choose a location to save the HTML file and click "Save". To import your bookmarks back into Firefox after reinstalling, go to the "Import and Backup" menu in the Library window and select "Import Bookmarks from HTML". Browse to the location where you saved the HTML file and select it, then click "Open".

Unfortunately this is only Firefox forum user help this isn't a support forum per say.

Oh really, just search for Support Forum in https://support.mozilla.org/en-US/#search with the Help Articles Only selected on top of search results.

This is a support forum not just for desktop Firefox but for a number of other things.

Look at top and hover over Contributor Tools > Support Forums which is https://support.mozilla.org/en-US/questions/

You have been here how long now giving low quality replies and still think this is not a support forum?