Gmail on iphone not working?

I can't get my email (Gmail) on my iphone. Error message: 'The mail server "imap.gmail.com" is not responding. Verify that you have entered the correct account info in Mail settings." I didn't change anything and all my settings appear to be correct… What should be IMAP Path Prefix be?

You need to make sure that your password and username are still the same on your phone's settings. If you change your password, that comes up sometimes.