“The user name or password for imap.gmail.com is incorrect” should be a common Mail app issue on iPhone or iPad that really annoys users. The problem exists constantly even you attempt to do any things with your Gmail account to make sure having correct account information. Look at our following tip to fix the problem.
It won’t be long to get rid of the problem when you can not get Mail due the “The user name or password for imap.gmail.com is incorrect” error:
Step 1: Logout your affected Gmail account totally from all devices such as other iPhone, iPad and web-browser on PC.
Step 2: From iOS on iPhone or iPad that you are facing the trouble, go to the following page via Safari: http://www.google.com/accounts/DisplayUnlockCaptcha.
Step 3: Follow the instruction on the page by providing your right Gmail address, password the confirmation Characters in the picture to verify your google account.
Step 4: Try to login your Gmail account into your Mail app on your iPhone or iPad again, and the problem should be solved.