any clue about how to change SMTP settings on an on-premise installation after first time setup?
Any help would be appreciated.
The SMTP proxy settings, which are set during the initial configuration of App Center, are saved in the Postfix configuration file. You can follow these steps to disable the proxy settings, and allow Postfix to send e-mails directly:
This will then remove the proxy/relay, and Postfix will then attempt to send e-mails to the recipients directly.
Let me know if this answers your question