I'm heavily afraid this is a FAQ, but I couldn't find anything.
Short form: My impression is that not fully qualifying the value of relaylhost
causes Postfix to only look up AAAA records for it.
Long form:
I'm on NetBSD 6.0_BETA/amd64 with the supplied Postfix 2.8.8.
Basically I have the default configuration but myorigin=$mydomain and
relayhost=smtp (I also have two masquerade options, full postconf -n at the
end).
Apperantly, Postfix only tries to look up an IPv6 address for "smtp": I get
Host or domain name not found. Name service error for name=smtp
type=AAAA: Host not found
and
warning: relayhost configuration problem
Fully qualifying the relayhost parameter (e.g. relayhost=smtp.math.uni-bonn.de)
solves the problem.
Is this a known issue? May it be NetBSD (or NetBSD 6.0) specific?
Full postconf -n output (AFTER the change):
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/db/postfix
debug_peer_level = 2
html_directory = /usr/share/doc/html/postfix
inet_protocols = all
mail_owner = postfix
mailq_path = /usr/bin/mailq
manpage_directory = /usr/share/man
masquerade_classes = envelope_recipient
masquerade_domains = math.uni-bonn.de
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases
queue_directory = /var/spool/postfix
readme_directory = /usr/share/examples/postfix
relayhost = smtp.math.uni-bonn.de
sample_directory = /usr/share/examples/postfix
sendmail_path = /usr/sbin/sendmail
setgid_group = maildrop
unknown_local_recipient_reject_code = 550
