550 5.7.1 We do not relay

Server is not open for relay. If you cannot send a message and server's response is 'we do not relay', the problem is probably that you are not authenticated.

SMTP Authentication - This is enabled by default and requires a valid User/Password to be used before SMTP sending is allowed.You should ensure your e-mail client is set to authenticate it's SMTP connection.

Links:

How to set up and use mail services with SMTP Authentication

Applies To

SMTP Error Codes

See Also