@Quasdunk
postfix/local...
Postfix is trying to send email to the local system user info, maybe email from some daemon running in your system.
Try to edit /etc/aliases and add:
And run:
------------------------------------------------------------------------------------------------------------------
@zebras
You can't connect to the remote server. Reasons are firewall issue or your isp is blocking the port 25. Check your firewall, open port 25 and test again.
Final step is asking your isp
Cheers