It appears that there is a disconnect between the apple id and the password within the the mail server for “x” number of accounts. Almost as if the password field was blank in the “database” (for lack of a better word).

This problem has been occurring since the release of iCloud. According to an Apple Senior Advisor it had everyone in support stumped.

Some people have been able to fix this by using the following procedure.

1. Go to https://appleid.apple.com/
2. Select Name, ID, and Email Address section
   • Look for duplicate email addresses as the primary and alternate
   • Remove any duplicates
3. Select Password and Security
   • Look for any missing information for security and password retrieval
4. Click ‘Change Password’
5. Enter in old password, new password, and verify new password as directed
6. Click Save Changes
7. Go to www.icloud.com
8. Enter user id and your new password
9. Open Mail on your Mac
10. Navigate to Mail > Preferences
11. Click Accounts
12. Under Accounts select iCloud and delete it by clicking the – in the lower left hand corner of the window.
13. Click the + in the lower left hand corner to add an account.
14. If not populated, enter in Full Name and Email Address (it should already be there).
15. Enter in the new password and click Create.

At this point the Mail program should go through a verification process and eventually create the iCloud account and begin loading all of your email, notes, news, etc.