
While using Outlook with Exchange server a user can have to face several kinds of errors. Most common among them are the SMTP errors.
Common SMTP errors are 550 5.7.1 'Unable to Relay', error code 5.0.0, 5.7.1, or 5.7.3 etc. 501 5.7.1 is another error code that can occur if there are problems while relaying email through Exchange. Just like 550 5.7.1 it also indicates that the user email client failed to authenticate on the mail server.
These error codes basically...