SMTP -> ERROR: Password not accepted from server: 535-5.7.8 Username and Password not accepted. Learn more at 535 5.7.8 https://support.google.com/mail/?p=BadCredentials s4sm29416246pfb.55 - gsmtp
SMTP -> ERROR: MAIL not accepted from server: 530-5.5.1 Authentication Required. Learn more at 530 5.5.1 https://support.google.com/mail/?p=WantAuthError s4sm29416246pfb.55 - gsmtp
The following From address failed: poponix@naver.com : MAIL not accepted from server,530,5.5.1 Authentication Required. Learn more at 530 5.5.1 https://support.google.com/mail/?p=WantAuthError s4sm29416246pfb.55 - gsmtp

SMTP server error: 5.5.1 Authentication Required. Learn more at 530 5.5.1 https://support.google.com/mail/?p=WantAuthError s4sm29416246pfb.55 - gsmtp