I am setting up my own email server for the first time and I am trying to figure out how to how to setup the smarthost with Postfix. I read in the pdf guide on how to enable the relayhost in main.cf, but I am getting all mail returned with:
Remote-MTA: dns; mxsrv1.spamgateway.comodo.com
Diagnostic-Code: smtp; 550 message submission is for authorised users only!
I’m sure I should be using Transport and the sasl_passwd file, but what credentials and how should it be setup? Can I use one set of credentials or do I have to have them for every different outgoing email address?
This trick seemed to work. All mail is now being sent with no authentication issues. I am getting an error that seems to be related to TLS and my self-signed certificate, but the mails are sending anyway.
certificate verification failed for mxsrv1.spamgateway.comodo.com[22.214.171.124]:587: self-signed certificate