I'm seeing this problem all over the web and I'm asking the same thing. I am not very computer savvy and would appreciate an answer that is easy to understand.
When I try to access my Gmail account on my iPad by clicking on the mail icon that came with the device (meaning: I'm not using my browser to access my mail and not using any downloaded apps) I get this message:
The mail server "imap.gmail.com" is not responding. Verify that you have entered the correct account info in Mail settings.
And I have. And do. Everything is correct. This started to be a problem before the new ios6 update. And I can access my gmail account on my iPhone just fine. This problem is just on my iPad 2.
Also. I do have another gmail account set up on my iPad and that email works fine. They both have been on my iPad for ever and both been fine until a few weeks ago. Just one account is messed up! Why? And why hasn't this been fixed?