SMTP server error: AUTH command used when not advertised

I get:

Failed to send test email! - Please check your outgoing email settings and server config to see if selected ports are open. Error details: The following From address failed: noreply@delawarevalleynews.com : MAIL not accepted from server,503,AUTH command used when not advertised

SMTP server error: AUTH command used when not advertised

SMTP server error: AUTH command used when not advertised

when I test the connection for smtp sending. I tried adjusting my servers settings to allow it with no result. I installed wp-smtp and entered the same credentials, and it succeeds.

domain delawarevalleynews.com I activated support access if it helps