I frequently send messages from Helpmonks in different languages. Therefore, I manually modify different attributes of my default signature.
It would be convenient, if I could choose from a few saved signatures. Similar to inserting a saved reply.
You can already add different signatures per mailbox.
However, signatures per language are not possible. We take it into consideration and added it to the Trello RoadMap under ideas: https://trello.com/c/r4g6krmv