Re: postfix chroot problem
Victor Duchovni
> Sorry that my question was not propperly formatted before. Here's another shot at it.
>
>
> ERROR MESSAGE:
> ******
> Feb 23 13:03:41 [postfix/smtp] warning: no MX host for mechno.com has a valid A record
> Feb 23 13:03:41 [postfix/smtp] ECC4240EB8: to=<pbl...@mechno.com>, relay=none, delay=1, status=bounced ([mail.jojosarfo.org]: Name o
> r service not known)
> ******
>
> This is what it logged when I attempted when I tried to send mail to pbl...@mechno.com, but yielded similar results for any outgoing mail.
> To me, this indicates that the system is able to look up the MX record, but when it attempts to look up the A record of the resulting MX record, it fails.
This is correct, the MX lookup yields results, but the hosts in question
have no A records in DNS. One difference between the MX lookups and the
subsequent "A" lookups, is that the "A" lookups don't disable the domain
search list. So with:
example.com. IN MX 0 host.example.com
and
/etc/resolv.conf:
search example.net example.org
nameserver 127.0.0.1
The "A" lookups will be:
host.example.com.example.net. IN A ?
host.example.com.example.org. IN A ?
host.example.com. IN A ?
Perhaps your search path in the chroot jail lists domains which don't work
(lookups return SERVFAIL rather than NXDOMAIN). Does the resolv.conf
in chroot jail match /etc/resolv.conf, is the chroot jail resolv.conf
world-readable?
> smtp started working correctly, though, when I turned off the 'chroot'
> option in master.cf
So DNS A lookups work outside the chroot jail, see above.
> --main.cf non-default parameters--
No smtp_host_lookup override...
> --master.cf--
> smtp unix - - - - - smtp
> relay unix - - - - - smtp
No master.cf "-o" options.
> -- end of postfinger output --
>
>
> Once again, I appeciate your time immensely and hope that you can help me to shed light on my problem.
If all else fails, write a test program that chroots into the Postfix
jail, drops root privs (becomes "postfix") and does DNS lookups... Do
"A" lookups with RES_DEFNAMES and without RES_DEFNAMES, do "MX" lookups
without RES_DEFNAMES. Report the results.
--
Viktor.
Disclaimer: off-list followups get on-list replies or get ignored.
Please do not ignore the "Reply-To" header.
To unsubscribe from the postfix-users list, visit
http://www.postfix.org/lists.html or click the link below:
<mailto:majo...@postfix.org?body=unsubscribe%20postfix-users>
If my response solves your problem, the best way to thank me is to not
send an "it worked, thanks" follow-up. If you must respond, please put
"It worked, thanks" in the "Subject" so I can delete these quickly.