Requires: - An external text editor (I'm using “gvim -f --socketid %w %s” in text editor entry) - A Claws Mail account with a configured signature Steps to reproduce: - Enable editing with a external editor - Reply to a message or compose a new one (account signature is correctly added) - End editing with external editor (leave signature untouched) - Mail body is now in compose window - Try now “Message/Replace signature” menu option in compose window Result: - A new signature is added below current, message has now two signatures. Expected: - Existing signature is replaced.