We recently switched from managing our own email on a HostGator VPS to using Google Apps. Here are my DNS records http://network-tools.com/default.asp?prog=dnsrec&host=custom3dprint.com.
I kept getting errors when sending such as "Relay access denied" and couldn't figure out what was going on. Somehow, email is still being routed over to our VPS before going to Google and Postfix was blocking it with this line of the main.cf:
smtpd_recipient_restrictions = permit_mynetworks, check_client_access pcre:/var/spool/postfix/plesk/no_relay.re, permit_sasl_authenticated, reject_unauth_destination
I followed instructions at the end of this post and modified that setting to allow Google and it seems to be working in my immediate tests.
The question is, should email be touching our VPS server at all? It seems DNS would point it straight to Google without a middle man. If I am correct on that assumption, what is wrong with my DNS settings that would cause this interference?