Outgoing email (for example app.telemetry notifications) can be deliviered using a so-called smarthost or relayhost. It is possible to configure this in the management center in SMTP-Settings.
Some email servers however require additional configuration.
Advanced settings for the service responsible for email delivery (postfix) are read and applied on service startup from all files in /config/postfix with the .conf extension.
Changes in those files are only applied after a restart of the postfix service and are persistent across product updates.
systemctl restart postfix.service
Some email servers only relay emails after successful authentication. In this case the following settings in /config/postfix/override.conf can be used to set this up.
smtp_sasl_auth_enable = yes
smtp_sasl_tls_security_options = noanonymous
smtp_sasl_password_maps = hash:/config/postfix/sasl_pass.map
The required credentials need to be placed in the file /config/postfix/sasl_pass.map using the following format:
hostname_of_the_relay username:password
Currently the following methods are supported for authentication and are automatically negotiated with the mailserver: PLAIN, LOGIN