I've a server with both IPv4 and IPv6 interfaces. Postfix is multihome, one instance, named postfix, is IPv6 only, and another, named postfix-kupec, is ipv4 and ipv6. Here's an output from postconf: aikipooh /home/pooh/metagrocery # postconf -nc /etc/postfix-kupec|grep inet inet_interfaces = [2a02:2b88:2:1::764c:4], 46.28.111.66 inet_protocols = ipv4 ipv6 When sending to google for example, it sends fine, but if the host is IPv4 only, it fails due to it is unable to locate the AAAA record for...
