Mozilla Thunderbird: Customizing automatic signature placement in e-mail replies

I have a signature block that I automatically insert into my e-mails.

Works fine except for one thing: The signature block is inserted at the bottom of the e-mail, after any text that is included in my replies. What I end up doing is cutting the signature block from the bottom, pasting it at the top, and typing my response there.

I'd like Thunderbird to insert my signature block at the top of the e-mail message. Is there a way to do this?

This is probably because you have the default setting, which starts your reply at the bottom.

In Tools -> Account Settings -> Composition and Addressing you can change the placement of your reply in the dropdown box:

You'll probably want to change it to start my reply above the quote. After you've made the change, the dropdown box below it will appear, which allows you to change your signature's placement as well. Change that to below my reply instead of below the quote.

In Thunderbird go to Tools >> Options >> Advanced >> Config Editor

Then search for mail.identity.default.sig_bottom and set it to FALSE by double-clicking it.

Your signature will now be above the text of an email to which you are replying or which you are forwarding.