Relaying disallowed as root@localhost SMTP code: 553

Relaying disallowed as root@localhost SMTP code: 553

I am setting up the smtp config as follows. I am using a password generated for the app instead of my main password. I am getting Relaying disallowed. Can you tell me what is the problem?

Error:
Unable to send mails:SMTP Error: data not accepted.SMTP server error: DATA END command failed Detail: Relaying disallowed as root@localhost SMTP code: 553