How to tell Thunderbird to Request Confirmation Before Deleting an Email or Empty the Trash

How to re enable confirmation warnings before deleting an email or Emptying the Trash Folder on Mozilla Thunderbird

I tend to delete emails from Thunderbird using SHIFT+DEL out of habit when I’m sure I don’t want that message any more, but recently I accidentally ticked the check-box that tells Thunderbird not to ask me if I’m sure I want to delete such message(s).


Although safer, I didn’t want to delete messages then empty the trash. For whatever reason I wanted to return to the past behavior. In case this has happened to you, here are the steps to get the warning back:

  • Go to the Tools Menu
  • Click on Options
  • Click on Advanced

The picture below shows the Options-Advanced Window. In the lower right you’ll see the “Config Editor” button. Click on It.


You will receive a fair warning as this. Click on I’ll be careful, I promise!


Now you’re on the configuration section. The value I want to change here is:

mail.warn_on_shift_delete   from false to true. To change the value, just double click on the line.


If you want to re-enable the confirmation for emptying the Trash folder, the value you should modify is:

mailnews.emptyTrash.dontAskAgain    from true to false.

* Mozilla Thunderbird Version 38 used.


I hope this information is useful. Buy me a coffee?
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7 thoughts on “How to tell Thunderbird to Request Confirmation Before Deleting an Email or Empty the Trash

  1. This is very helpful. I needed this. Thank you very much!

    Here are two other related flags for confirmation dialog boxes in Thunderbird (using 60.9.0) that may be helpful to someone:



  2. My Thunderbird screen does not have an ‘options – advanced’ window. Can’t see anything that gives me this choice – anyone else found this, or a solution?


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