If a received message opens like it's a draft, you might be able fix it by applying the FolderFlags 1.7.0 add-on:

https://addons.thunderbird.net/en-us/thunderbird/addon/folderflags/versions/

https://support.mozilla.org/en-US/questions/1414262

Sorry but none of this works. Have installed Folder Flags and tried another fix from a related question in the forum. Still opens messages in a Save screen with the warning message as I sent in my original question. It is also constantly "Not Responding" when I try and do anything at all. Blimey!

I would just add that there is no Refresh option where it should be.

Where is Refresh supposed to be? Did you right-click the folder, Properties, and adjust the Flags tab, then restart TB?

Where is Refresh supposed to be? Did you right-click the folder, Properties, and adjust the Flags tab, then restart TB?

Thanks, but I am sorry you are dealing with an idiot here! Where is the folder Properties in Thunderbird? Very sorry - this will be a test of your patience.

If it is any use to you, this is what it looks like when I try and open an e-mail.

Well here's an interesting one: if I right click an e-mail in the Inbox, go to Open then Open in a New Tab, it displays fine even it is headed as a Draft Messge. The plot thickens!

Where is Refresh supposed to be? Did you right-click the folder, Properties, and adjust the Flags tab, then restart TB? Thanks, but I am sorry you are dealing with an idiot here! Where is the folder Properties in Thunderbird? Very sorry - this will be a test of your patience.

See the attached pictures. An Inbox should not have the Drafts box selected.

My sincere thanks to you for your time and trouble. It is very much appreciated. We are now sorted and it's behaving as it should do! Howard.