I'm attempting to use just 1 postfix instance to input ALL my outgoing mail. From there the goal is to relay it to my one of the many outbound postfix instances. I do this using round robin dns so it spreads the load throughout.
[mail client] --> (main instance) --> (outbound instance) = DOES NOT WORK
[mail client] --> (outbound instance) = Works Fine
Below is my relevant main.cf for the main input postfix instance:
smtpd_sasl_auth_enable = yes broken_sasl_auth_clients = yes smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth smtpd_sasl_security_options = noanonymous smtpd_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination relayhost = [mta-mx-1.outbounddomain.com]
It should relay to
mta-mx-1.outbounddomain.com using the username and password combination in
Below is the relevant main.cf for an outbound postfix instance:
smtpd_sasl_auth_enable = yes broken_sasl_auth_clients = yes smtpd_sasl_type = dovecot smtpd_sasl_path = private/auth smtpd_sasl_security_options = noanonymous smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
I thought I could shovel all my mail through one server at full speed and let it relay evenly through all servers. The idea was to attempt to send mail through this group of loosely configured postfix instances. Then if/when anything fails, fallback_relay to a tighter configuration (ie: mta-mx-2.outbounddomain.com, etc).
When I tried to send mail from the mail client (tbird) through the main instance, I get relay access denied (554). It makes the connection to the outbound instance, but authentication never seems to take place. When I try to send mail directly without relaying first, using the same credentials, mail goes through just fine.
Is there something I'm missing? What is making it show relay access denied when sending from the main postfix instance and not when sending direct?