If you have chosen to open emails in a tab then that is precisely what occurs. If you do not close those tabs then the session remembers what was left open as according to your instructions and it attempts to keep them open.

This is not something to complain about. It's your actions that determine whether something opens in a tab or not. It's also your actions that determine whether to close a tab or not. However, it seems you are not understanding why it's occurring in the first place. Wanting to complain to the developers is a bit like you wanting to complain to the London Mayor because you bought too many packets of frozen peas in Tescos. So this is the forum where you ask about issues you do not understand or need help to sort things out. In that respect, you are in the correct place. So let's try to get you sorted.

What can cause emails to open in tabs: If you have the 'Message Pane' enabled, then a single left click will open the selected email and display it below the Message List in the 'Message Pane'. If you double click on an email then that is the instruction to open the email in a 'Tab' by default.

In the Message List:

• If you use 'threading' of emails and a thread is in a 'collapsed' state, you will see a chevron > just to the left of the Subject.
• If you do a single left click on a collapsed thread then it will display X number of Conversations in the 'Message Pane'.
• If you do a double click on a collapsed thread then that is the instruction to open all emails that are a part of that thread and open each of them in a new tab.
• If you clickon the chevron > then it will expand the thread revealing all emails contained therein. This means you can then clickon a single email to see it's contents in the 'Message Pane' or do a double click to open that specific email in a new tab.
• In all cases you can right click on an email and select 'Open' and it will offer various choices.

To close tabs: To close just one tab you can click on that tab's 'x' icon General option: Right click on the tab and select the desired option. If you want to just keep the Mail tab open - it's always the one on the far left and it might have same name as a folder you selected eg: Inbox - But close all others: Right click on the 'Inbox Mailbox tab' and selct 'Close other tabs'

As you have an issue with Thunderbird not starting and you think it's due to you leaving a load of tabs open then try the following:

Do not attempt to open Thunderbird. You need to access the Profile. I'm assuming you got the Thunderbird email client program from the official website: https://www.thunderbird.net/en-US/thunderbird/all/

I'm also assuming you are using a Windows OS computer. So if you have a different OS or got Thunderbird from a different location then please tell us. That means the profile by default should be in this location:

• In windows search type: %Appdata% - see image below as a guide
• Select %Appdata% file folder
• Select: 'Roaming' folder
• Select: 'Thunderbird' folder
• Select: 'Profiles' folder
• Select: the profile name folder eg: 123abcd.default-release

Look for the following files and delete them:

• session.json
• xulstore.json

Let's see if resetting the session data etc sorts out what is remembered.

Now start Thundrebird. Report back on results.

I don't think the analogy with the London mayor is correct. I did not decide that Thunderbird would start opening tabs every time I opened an email, or make a long list of emails that I opened and can close with the red X. The program did not used to do that. Now, since it does, it causes a long delay to see my inbox while the tabs or the list comes up. I think it caused my program not to open today.

I had to spend a lot of time to do a shut down (after the sleep option changed nothing), and then to open thunderbird again after restarting. It opened that time, but it still takes so long.

I don't know what you mean by "message pane" enabled.

I looked for menus with the word message, and nothing happened when I clicked on those.

"If you double click on an email then that is the instruction to open the email in a 'Tab' by default."

THat is specifically the problem. By default. That means it is a programming decision made a few years back, not in the original program. There seems no effective way to turn off that option, and no link to click to go directly to the inbox. They told me to press Ctrl 1 but that usually doesn't work.

Whether I want tabs or not, they come up, and slow down opening the program. I know about "close all tabs" but that option is available only once the program opens. Right now, I want a lot of those tabs open. But I know I have the option of closing them and searching among my emails and their threads. That takes a while too. Or they come up in the long list that appears. My basic point is there should be an option somewhere to go directly to the inbox so I can see incoming messages. Whether lots of tabs are open or not. I still don't see or know of one that usually works.

"You need to access the Profile." I have no idea what "profile" is, without even opening thunderbird.

I use windows 7, and I will NOT upgrade.

You are discussing this problem in two threads, the other is at https://support.mozilla.org/en-US/questions/1545457 I will stand by instead of responding to the other.

True David, I will lock this.