I use Google business some of the apps interact with gmail. When you open a email under in the footer of that email you get a information box of the app, then it can get data of that email and put it in a system..
Start mail.google.com --> get email and open --> go to the box under the email --> do something in the box with the data of that email..
How to build the same app functions but for our self, doe i need Google app engine or do i need Google apps script. Some links would be helpful
gr.
Google App Engine is just a host for web applications and has nothing to do with access to Gmail.
In order to access Gmail data, you may want to create a Google Apps Marketplace App. You will have do decide what data you want from the email, and ask for the user to approve the correct OAuth2 scopes.
What you need is to write a gmail contextual gadget. You can do it with appengine or any other provider. You dont need to use the gmail api since the contextual gadget already gives you all the necessary data (except attachments). The other answer says you need to use oauth scopes to access the mail which is incorrect. You can publish the app anywhere you want including the marketplace. See: https://developers.google.com/gmail/contextual_gadgets
As Zig mentioned Gmail Contextual Gadgets are one way, but I'd recommend evaluating Actions in the Inbox. It can provide a better user experience over gadgets from both visibility and performance. It does require that you register with Google but you can start development today.
