Z10 says my email password has changed. It has NOT. How do I get around this

One of my yahoo email accounts would not update on my BB Z10, stating that either my email address or password had changed. They had NOT changed, but when I went in and rewrote the information, it would not accept it.

I deleted the "broken" email off my phone, restarted phone and tried to reinstall but I get the same message.

My IMAP and SMPT information is all correct.
My personal email address and password is correct.

Phone will not accept it.
Secondary yahoo mail is still functional.
Primary yahoo contacts is still functional.

HELP!