Even properly configured, seeing intermittent "MX list for foo.com. points back to mx4.mailhost.com"
From: loonux fc (loonux_at_gmail.com)
Date: Wed, 9 Mar 2005 19:51:11 -0500 To: email@example.com
I am trying to debug a mysterious problem. We run several mail
servers, of which in total we probably handle upwards of 1 million
messages a day. Our mail hosts are set to relay mail to their
ultimate destination. In order to do that, sendmail is configured as
1. "foo.com" is added to /etc/mail/relay-domains
2. The following entry is added to mailertable:
3. An entry is made to /etc/hosts for mailhost.foo.com:
This is how it should be, and it works 99.99999% of the time.
However, on what appears to be completely random occasions with
completely random customers, the dreaded message will pop up:
Mar 9 08:09:38 mx4 sendmail: [ID 801593 mail.crit]
j29G8qR07010: SYSERR(root): MX list for foo.com. points back to
And, the message is bounced back to the sender with the usual "local
configuration error" line. However, all around this line are signs
that the system is indeed working as it should; for some reason, it
simply appears that sendmail is not honouring the mailertable entry,
or is somehow unable to consult /etc/hosts and is ignoring the
mailertable entry. There appears to be no correlation with anything
bad happening on the system: there are no other errors reported, and
other mail transactions happening at the same time are processed
I'm running Solaris 8/sparc on Netra T1's with 256Mb memory, running
sun-supplied sendmail (8.11.7p1+Sun). My /etc/resolv.conf lists
"files dns", although I do not think this is applicable in this case.
The only odd thing about our mail handling is that we run two daemons:
one to accept inbound mail and drop it into a queue, and another to
flush that queue on a regular interval.
Note that A records for "mailhost.foo.com" do not exist in DNS, only
in the system's /etc/hosts.
Has anyone else experienced such strange intermittent issues as this?
Thank you for any help that you can provide.
sunmanagers mailing list