This mailbox is not syncing and needs permission to resume.

[AnuFoto]

Hello. I just received this error message from yahoo:

¨This mailbox is not syncing with Yahoo and needs permission to resume. This can happen because a security setting or password was changed.
Sign in to Yahoo¨

And when I sign in with the email add. in question, it says:
¨Sorry, we don't recognize this email.¨.

I have been using this email add. for the past 2 years and it is my work email. So I need urgent help because I am not receiving any messages to it nor am I able to send from it.

Please help.
Thank you very much and have a great week.
Kind Regards.

Anu N.