Originally Posted By: Mike
It happens with both, the 'Mail' app and on the web. I got part of the 'error' message from the web page. I don't think I've had a brain fart because I never have to type in my password when opening the Mail app. And I've received e-mail just fine until yesterday afternoon.
The computer was off for the past few days. I hardly use it anymore and get my e-mail on the iPad where I repeatedly get this 'incorrect username or password' message. Again, I have it set up where I don't have to type in my password every time.
I don't get it........ mad
It has to be with Apple then. According to the link below there is no current problem, but it is not always accurate, they take a bit of time to post problems sometimes.

http://www.apple.com/support/icloud/systemstatus/

You can try the Contact Support button at the bottom. I've never used it so I don't know what frustration level it may take you to. smirk