LR Classic No Longer Exporting Email via Apple Mail

Over the last five years I have exported many hundreds of photos from LR via Apple Mail - until this morning.  Apple Mail is no longer an option to select under the 'From' window in the email export box.  

I'm using Mac OS Catalina 10.15.5 and LR Classic 9.2.1.

I've looked through a few posts describing a similar issue, but I haven't seen a solution that adds Apple Mail back to the drop down in the 'From' window.

Any help would be appreciated.