I have seen a mouse going bad and issuing a double click instead of a single click delete 2 at a time. Do you have a spare mouse to try?

No extra mouse but I will get another one to see if this helps but I will buy another one tomorrow. Thanks for the suggestion.

like I said on your other thread, if you click on the mail and press the delete key on the keyboard do you loose more than one mail?

I apologize for not responding sooner. I misunderstood exactly what you were saying. I was using the Delete function in the program but when I reread to see what you meant, I used the Delete on the keyboard and this worked w/o losing other emails. I don't understand why this is happening nor do I understand the other issues that are going on. When I click on an email to open and read (not in larger window but in divided pane) it goes ahead and opens up and fills the screen.

I have uninstalled and then downloaded and started all over. Another poster suggested it was the mouse and I do plan on getting another one since I had already given my spare to a friend. However, the mouse causes no problems elsewhere or in other programs, only in Thunderbird.

I also wish to apologize for posting twice; I am unfamiliar with this particular forum and I had no desire to confuse or anger anyone. I thought for whatever reason that my first request didn't show up so I tried again.

Again I do appreciate your help.

multiple deletes would indicate multiple events from your mouse., opening a tab from a single click indicates Thunderbird is getting a double click. Airmail sauid your mouse is sick. If it is cordless, it might need a new battery.

Or may just need to calibrate the click speed

Start menu > control panel >Mouse > Pointer options and Start menu > control panel >Mouse > Buttons

I went into the mouse settings and also messed with other settings and at least I now have a better working Thunderbird. I still have to use the Delete key on the keyboard to make sure only one message is deleted but I can live with that.

Thank you for your suggestions and help; it is appreciated.

Matt said

multiple deletes would indicate multiple events from your mouse., opening a tab from a single click indicates Thunderbird is getting a double click. Airmail sauid your mouse is sick. If it is cordless, it might need a new battery. Or may just need to calibrate the click speed Start menu > control panel >Mouse > Pointer options and Start menu > control panel >Mouse > Buttons

I recently developed that same problem. Restarting TB helped for a day or two, but then it came back. I slowed down the mouse speed and now it seems to be solved. I never would have thought of trying that in 100 years. So THANK YOU!