Solved: Cannot Get Mail imap.gmail.com not responding

The mail server “imap.gmail.com” is not responding. Verify that you have entered the correct info in Mail settings.

There are a couple workarounds / Fixes for this error, but the one that worked for me on my friend’s white iPhone 4s was to simply visit this website: https://www.google.com/accounts/DisplayUnlockCaptcha and remove the CAPTCHA from the gmail account.

http://www.gmailinformation.com/blog/gmail-imap-not-responding/