Thunderbird : Why there isn't "--" before signature when respond whereas it appear in new message?
I'm on Mac with Thunderbird 10.0.2.
I've a simple text signature.

When I write new message , TB automatically add "--" before signature.
When I click on respond to a message, it doesn't add it.

How to have the "--" always appear in message i wrote before signature ?

Thanks 
Thunderbird : Why there isn't "--" before signature when respond whereas it appear in new message?
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I'm on Mac with Thunderbird 10.0.2.
I've a simple text signature.

When I write new message , TB automatically add "--" before signature.
When I click on respond to a message, it doesn't add it.

How to have the "--" always appear in message i wrote before signature ?

Thanks 