further to above I tried working through the menus and found an option under Edit, Folder Properties, Repair Folder which I ran, after which all emails deleted since 29 July were now visible which solved the immediate issue if not the question of how to change the default behaviour of message deletions which I'd still like to know. thanks

I do not know that the settings for delete functions in account settings have fundamentally changed in the past 10 years. Mine in V102 look like this

That's interesting, mine look like the attached image*. No option for When I delete a message & also instead of the Account name being an email address (devilsgatedrive@:gmail.com) instead it's a name only (SuziQuatro), and it's the same on all 4 of our PCs. I'm also intrigued by your version being V102 whereas my Thunderbird is only v91 & I'm on the release channel with the latest update. (My Firefox is v103).

• if it works, haven't tried adding an image before

thanks

V102 has been release for new installs and the brave (or foolish) have downloaded it and installed it. General updates for the masses are still being held up until some of the nastier bugs the brave and foolish found are fixed, but general updates will be enabled soon is my understanding.

Your account is POP and this is very important as how things woirk is completely different for POP and IMAP protocols (my image was IMAP as that has been the default for new accounts for about 10 years now)

POP is rather old school, and sometimes harder to fix because it has no synchronization settings.

So the first thing to establish is does the account actually have a trash folder? ( found an old image from V91. Check your icon if you have the folder against that shown in the image.)

Do you have a trash folder and does it have the correct icon?

Thanks - yes I have a trash folder and it shows the same dustbin icon as is in your example above. Since I ran the folder repair all my new and old deleted messages are visible and accessible and it all works as it left the factory, so there's no problem. Looks like it may just be a difference between the POP and IMAP functions. It's no problem for me, just re-assuring to know the reason for it. Thanks for your help.