A google app script that will allow you to detect YesWare infected emails and mark them as read, and warn you about them by adding a tag on the email.
Yesware annoys the shit out of me, and is a incredibly good sign that I don't want to read the email ( sales, or very crap recuritment attempts )
You can find install instructions on my other app scripts repo: https://github.com/benjojo/Gmail_GeoIPTagger
Example view:
