If you care about nature, you might decide to ask your recipients not to print your emails.
Just add a green message addon to your signature following these steps:
Click Addons tab in the signature editor.
Choose the Green message from the list of available addons.
Choose a type of green message from a drop-down list - one of the ready ones or with your custom text.
Choose one of the icons or set it to none.
Choose a font size from the drop-down list.
That's it, you have added a green message to the signature ;)