Hello There, Clark,
Before I go into greater detail regarding my skills and experiences, I'd like to take a moment to talk about your specific requirement:
This sounds like a fairly straight forward project and I actually have a couple of ideas on how to construct this for you. I do have one question that I'd like to get out of the way. You mention that you'd like to extract from email like Google Mail... Is that the ONLY email provider that this needs to work with? As far as programming for email is concerned, gmail is a little different than most of the others, so it requires some additional custom coding.
As far as installing the app is concerned...why not eliminate this potential bottleneck and go web based? Yes, it can store the images on the user's computer even if developed for the web. This is a strength of HTML5.
As for removing the images from the inbox is concerned, this is absolutely impossible with gmail and any other *hosted* email solution. Emails were never designed to be updated. That being said, this is possible with some email servers.
I have been developing web and software solutions for well over a decade now. I've worked with companies and government agencies around the world. I'm an American, but reside in Europe at least half of every year. One of our most significant value-adds is that I have significant knowledge on how business is conducted around the globe, specifically as it pertains to Information Technology.
Thank You
Brandon Osborn