In the same way gmail can generate ads based on email content, I am looking for a way to develop a system which can:

• Allow users to connect their email address to our site
• It then would continously monitor all incomming emails
• From the incomming emails there would be a critera(e.g. a certain address or subject) if any of the emails matched the critea it would would be saved to a database
• Then once a new email had been found the users would receive an email notification will tells them to log back into the site to see it.

My questions are:

1. Would this be possible?
2. What would be a good language to use(generally I like php, python and java)
3. Are there any frameworks which would help do this?
4. How would I connect the users email account to allow access to their emails(do I need a mail server?)
5. Any advice?

Thank you! If you need more information please let me know.