How to determine which app is creating a notification I am running Android 2.2 on HTC Legend. I have a LOT of applications installed on it.

Today, after I changed my mobile operator, a notification appeared in the top bar. When I click on it, it says that my connection to Google is wrong and asks for the password.

However, since this is a dialog overlay, I have no mean to know if it is an application that I can trust (like a native one), or some sort of scam.

Any idea on how to identify from which app/service this message comes from?
This method does not work on Android 2.2.

Tested on Kitkat Android 4.4.2

Long press the notification and select App info.
It will take you to the settings app and show the details of the app the notification comes from.

on Lollipop

A long press shows you the name of the application instead of the notification.