Email integration

Question

I was wondering if someone could help me out. In some web application, the app will send out emails, say when a new message has been posted. Then instead of signing into the application to post a reply you can just simply reply to the email and it will automatically update the web app with your response.

My question is, how is this done and what is it called?

Thanks

Answer 1

Generally:

1) Set up a dedicated email account for the purpose.

2) Have a programm monitor the mailbox (let's say fetchmail, since that's what I do).

3) When an email arrives at the account, fetchmail downloads the email, writes it to disk, and calls script or program you have written with the email file as an argument.

4) Your script or program parses the email and takes an appropriate action.

The part that's usually mysterious to people is the fetchmail part (#2).

Specifically on Mail Servers (iff you control the mailserver enough to redirect emails to scripts):

1-3) Configure an address to be piped to a script you have written.

4) Same as above.