554 Delivery Error: Remote Host Said: 554 Delivery Error: Dd This User Doesn't Have A?

Remote host said: 554 delivery error: dd This user doesn't have a? - 554 delivery error:

Hello, If I get a message from one of my Yahoo email account to another Yahoo email account I get an error message like:
Remote host said: 554 error: dd This user does not account ....... (Note that I e-mail)