The PDF preview tab in Thunderbird is fantastic!
I use it on all three major OS systems, and it allows me to open an attached PDF, annotate with text or insert a signature SVG to finish saving it.
This saves a lot of time for workflows where users send you a PDF for approval, you review it, sign it and then reply back to it. This has become the spontaneous form of authorizing actions in our company. Ideally, one last step would be added which allows you to reply with the annotated or signed PDF to the original sender.
To do this, a couple of things would be awesome additions:
1. Include an icon to Reply with the modified PDF to the sender that attached it.
2. Include another icon to Create an entirely new message with the modified (on screen) PDF so that you can pick an email recipient of your choice.
Thanks in advance for considering this idea.