Thanks for your help.  The answer lies in the second part of your instructions.  I needed to reinstall XPS Document Writer.  This was removed by a Windows 11 update.  I would never have guesed.  However, the Intuit instructions for reinstalling this are only good for Windows 10!  You all need to amend the instructions as I had to really hunt around for the correct sequence of actions to install and inititiate the program. Once done, we were able to email PDFs again.