The relay server you are forwarding your clean emails to, does not allow you to send email because requires authentication. The server does not allow you to add an exception for your Esva installation.
The solution requires root access to the appliance and brakes web configuration of the external smarthost (menù System->MTA Advanced Configuration External SmartHost).
Once logged in as root do the followings:
- cd /etc/postfix
- edit main.cf and add two lines as follows:
smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous
- edit sasl_passwd and add an entry like:
- postmap /etc/sasl_passwd
- service postfix reload