451 Temporary local problem - please try later
The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'xxx@xxx.com'. Subject 'test', Account: 'mail.xxx.com', Server: 'mail.xxx.com', Protocol: SMTP, Server Response: '451 Temporary local problem - please try later', Port: 25, Secure(SSL): No, Server Error: 451, Error Number: 0x800CCC79This is only happening to a single email account on the server...
Not able to send or receive from different locations, webmail, etc.
Any clue?