root@ETC_MAILNAME problem

This one falls into the “things I need to make a note of in case I hit the same issue again in the future” category.

Just before Christmas I was trying to do some funky stuff with Exim on Debian and, in the process of trying to achieve my goal, I did an apt-get upgrade to make sure I had the latest version, just in case that fixed the problem.

Unfortunately, it didn’t. Furthermore, all locally originating outbound emails started failing with an error similar to this one: root@etc_mailname: Unrouteable address.

Most solutions on the web will advise you to make sure that /etc/mailname and /etc/hostname both contain the FQDN of the host in question. However, you also need to ensure that the FQDN exists in /etc/mailname in TWO places, as per the snippet below: localhost localhost.localdomain

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

The key point above is making sure that the FQDN is defined not only for the IPv4 version of localhost but also the IPv6 version of localhost.

Yet Another Programming Blog

Where James Gordon rambles about PHP and web development in general.

Find me on Twitter Find me on Stack Exchange Find me on Github Subscribe