How is it not available? Is it simply not listed or is it there but greyed out?

You're not allowed to remove an account if it's set as the default. So if you're trying to remove the default account, set another as default first.

Another relativity common situation is that the user is determined to remove Local Folders and you're not allowed to remove that either. It has folders fundamental to Thunderbird's operation. This is sometimes made more complicated by the user having renamed it and then forgetting that he has done so.

It's greyed out. How do you set an Email Account as the Default Account?

Open Account Settings. Select the required account. Click Account Actions then click Set as Default.

Set as Default is greyed out.

That's the core of the problem. I can't remove an unwanted account, which I never use, because Remove Account is greyed out, and I can't set the account, which I use all the time, as with this exchange of emails for example, because Set as Default, is greyed out.

Please post your Troubleshooting Information. To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Clear the check box Include account names.
• Use the button Copy to clipboard to select all.
• Paste this in yoor post.

You might try this:

1) Go to the account that you want to KEEP USING. 2) Set that account as the DEFAULT 3) Go back to the account that you want to purge 4) See if the "Remove Account" option is now available, and if so, click it.

The theory behind this is that the account that you want to remove may be set as the current default, which means you couldn't delete it. But if you set a different account as the default, the status of the other account should then be "normal", and you'll be able to remove it.

Let me know if that works!

Apparently started here https://support.mozilla.org/en-US/questions/1175898 and continued here https://support.mozilla.org/en-US/questions/1176648

So I will lock this topic from further posts.