Learning IPv6 part 4 - Postfix email server

Postfix is very simple to install and was also pretty simple to setup for IPv6 use.

1. install the postfix and alpine programs (plus dependancies)
2. edit /etc/postfix/main.cf
   1. check the mydestination field includes the domain you have setup
   2. Ensure the mynetworks field includes the IPv6 network you are using (so for me I needed to add "[2001:470:1f09:12e9::]/64" to the end of the line
   3. added a line "mydomain=test_ipv6_domain.com" above the mynetworks line
   4. Add "inet_protocols = ipv4, ipv6" to the end of the file otherwise Postfix currently defaults to only listening on the IPv4 addresses
3. Add the relevant lines to the bind zone file
   1. @ IN MX 10 mail6.test_ipv6_domain.com
   2. mail6 IN AAAA 2001:470:1f09:12e9::123

Allow mail through the firewall to the IPv6 address and it all worked smoothly.

RDNS was a real pain until I realised I needed to register my DNS server with hurricane Electric on their tunnel setup page. Obvious when you think about it - the IP's are registered to HE, how are they to know what my DNS server is?

A partly usefull site is http://www.mxtoolbox.com which lets you check what it sees your DNS entries as, however it does not support IPv6 so shows the IP address as 0.0.0.0 - at least you know that it is working that far though. :) You can also check other DNS records on this site (NS, A, SPF, txt, PTR, CNAME etc etc etc.)

A better guide to Postfix setup which does not include IPv6 is here: http://www.linux.com/learn/tutorials/308917-install-and-configure-a-postfix-mail-server