I need a developer who is experienced with creating Gmail Add-ons. I want to create a simple Gmail Add-on that automatically sends an automatic email to any person who emails me that hasn't previously emailed me. For example the Gmail Add-on would search through my email and automatically determine if I have received an email from the sender previously. If NOT it would send an automatically generated message to the sender.
Please indicate with your bid how on a scale of 1 to 10 how experienced you are with creating Gmail Add-Ons.