In my gmail, I have a variety of email signatures. I know how to toggle between them using the standard gmail feature of selecting the pen at the bottom of the compose window, and I know how to have gmail automatically apply a different signature based on my "send from" address. What I want gmail to do is change the signature based on the contact and/or on the label applied to an email. I understand Mailbutler also has tags, which would also be fine-- if Mailbutler changed my signature automatically based on a tag, as long as the tag could get automatically applied based on the contact.