Building Web App

We are a market research firm and send out emails to prospects every week pitching our services. I need to build a web app in which we can upload our email lists, have it automatically check for people who do not want us to email them (i.e. those who selected "unsubscribe") and then allow us to download an email list that we can use. In more detail, here is what I need: a) Step 1: When we email people about our services, I want to include a link that says "unsubscribe me" in our emails. When people click on this link, I want them to see a web page that says "You have been successfully unsubscribed!.". In the background, I want us to capture their email id and store it in our web app that you build. This way our do not call list will automatically keep getting updated. At any time, I want to have the ability to go in and view how many email ids were captured. b) Step 2: See sample file attached. This is what our weekly email lists look like. The are smaller in size but are always different from the prior weeks lists. When we upload such an email list into the web app, it should automatically check all emails contained in this file against the "unsubscribed emails" that it has been collecting. c) Step 3: It should delete all emails where there was a match and allow us to download the cleaned file. In this cleaned file, basically there would be blank spaces in which earlier there were emails that belonged to the unsubscribe list. This web app will be used by my staff and I really want to make it very simple as people using this web app are not programmers but junior marketing people. So it has to be very easy to use. Does this make sense to you? If yes, Can this be done, how long will it take and how much for this? Please ask questions if you are unclear on [login to view URL]!