Opening email often appears in new window

[meRobs]

I recently installed Thunderbird 91.4.1 in an attempt to overcome issues I had with eM Client.
The issue I discuss here is that I wanted each email to open in the existing preview pane when selecting it with a single click from the Inbox, say.
In Thunderbird, I was pleased to see Menu > Preferences > General > Reading and Display > Open message in existing display window.
I checked it. This seemed to work on a number of occasions.
Logically, it should always work this way, after all, there is a Preview pane taking up the right half of the UI when the Vertical Layout is set. It is a display pane designed to display the message.

However, it often is not the case. A single click on an email in the Inbox often opens it in a separate window as well as in the display pane ?!!
Surely, Thunderbird was not designed this way?
It almost seems as if TB often sees a single click as a double.

I don't wish to uninstall Thunderbird and seek another email client.
Please help.
Thanks
Robin

[tanstaafl]

I normally read my mail in the preview pane. That is configured using view -> layout -> message pane (F9) , not tools -> preferences -> general -> reading & display. If I double click the message in the folder pane it does use whatever method is specified in "reading & display". I have it set to "a new tab". So if I accidentally double click its more convenient than it opening in a new window.

I suggest you modify the double click speed of the mouse. Lowering it might be better than speeding it up but you'd have to experiment to see which works best for you. You can't use the windows "settings" app. to modify that mouse property, you need to use the control panel to do that. If that doesn't help try setting mail.openMessageBehaviour to 3 (not a supported value) using the config editor (its available at the bottom of tools -> preferences, and is Thunderbird's equivalent of about:config).

"The mail.openMessageBehavior pref behavior...

0 - open a message using enter or double click in a new window
1 - open a message using enter or double click in an existing window
2 - open a message using enter or double click in a new tab (default)"

https://support.mozilla.org/en-US/questions/1199949

[meRobs]

I normally read my mail in the preview pane. That is configured using view -> layout -> message pane (F9) , not tools -> preferences -> general -> reading & display. If I double click the message in the folder pane it does use whatever method is specified in "reading & display". I have it set to "a new tab". So if I accidentally double click its more convenient than it opening in a new window.

Thanks Tanstaafl. I reverted the Reading and Display setting to a New Tab, as you suggest.
I had already been using View -> Layout -> Message pane (F8), so, all else was unchanged.

Yet, strangely, a single mouse click on items in the Inbox gives the desired response: opens in the Preview pane only -- I've tried it a number of times over the past hour and it continues to be well behaved !?
I say strangely because prior to my request for help, the behavior was not stable; it would work properly for some clicks and then would create new windows and vice versa.
All I did on reading your reply was
(1) change the Reading and Display setting and (2) check some of the other settings in Thunderbird, without changing them,
(2) re-booted the PC for a small BitDefender update (hence restart of TBird) and
(3) set Thunderbird as the default email client in Windows.
Previously, I had Thunderbird and eM Client both open with the latter as the default for emails.

Fingers crossed.
Thanks again

[meRobs]

Whoops. It failed again: just after linking Lightning to Google Calendar, a single mouse click on a message in the Inbox opened it in a new tab, particularly if the email was new (unread)!
This may be a coincidence.
Any suggestions?
I think I might try to remove the sync/link to Google Calendar?
Thanks

[meRobs]

Since I am sick of this issue, after playing around for another hour or so, I removed the Google calendar from Thunderbird. This made no difference!

Then, I changed the Mouse speed to the lowest possible setting via Control Panel > Hardware & Sound > Mouse. This also made no difference!

Looks like I'm stuck. Any suggestions?
Thanks

Edit: I guess the Mouse setting is ambiguous. I had set the speed to the far left, at 'Slow', but, as stated above this failed. Then, I changed the speed to 4 clicks below 'Fast' and all seems OK !??
For the time being, at least (here's hoping)

Edit; NO! Regardless of the mouse speed as set above, a single click on an Inbox item opens it in a separate Tab, maybe 20% of the time!!

[tanstaafl]

If changing the double click speed worked for a while and then suddenly stopped working, perhaps its the hardware. Try a different mouse if you have one available. I have to replace my Logitech M510 mouse approximately every 3 years when I start having problems positioning the cursor.

[meRobs]

Thanks again Tanstaafl. The fact that you keep making suggestions tells me that what I am asking for in Thunderbird is meant to be so.

So, I shall dash off and buy a new mouse!

Edit: just got a new mouse and it seems happy in its new home
If a make no further comment, all is well and thanks again!