Jeff Koch wrote:
A good pick up by Tren, I didn't think about tcpserver initially. As far
as I know, the only reason you will experience any sort of delay is if
the dns that the accepting server is not functioning properly. I have
taken to running a copy of dnscache on each of the front end servers for
qmail to use only as it is very lightweight and extremely fast and
simple to setup.
That being said, before moving to this setup I did have a problem on a
server which was having lots of trouble due to lookups failing and it
was giving 4xx temporary errors due to load and timing out connections.
Since moving to the above setup I have not seen a repeat of these
problems. Others may have different experiences that I would be
interested in hearing about as well.
Shane
#!/bin/sh
QMAILDUID=`id -u vpopmail`
NOFILESGID=`id -g vpopmail`
MAXSMTPD=`cat /var/qmail/control/concurrencyincoming`
exec /usr/local/bin/softlimit -m 8000000 \
/usr/local/bin/tcpserver -v -H -R -l 0 \
-x /home/vpopmail/etc/tcp.smtp.cdb -c "$MAXSMTPD" \
-u "$QMAILDUID" -g "$NOFILESGID" 0 smtp rblsmtpd \
-r xxxxx \
-r xxxxx \
/var/qmail/bin/qmail-smtpd \
/home/vpopmail/bin/vchkpw /bin/true 2>&1
Thanks for the clue. I see we're using the 'H' option which prevents
reverse DNS lookups. This configuration setup (with the exception of our
rblsmtpd entries) is a stock Shupp Toaster - so I guess the question is
why the stock toaster is configured not to do reverse DNS lookups when
doing so triggers the spamassassin 'RDNS_NONE' flag.
Any comments? Would rDNS lookups totally slow down a production server?
At 02:09 AM 12/30/2008, you wrote:
What switches are you using to call tcpserver with for your
qmail-smtpd process?
t
----- Original Message -----
From: Jeff Koch <jeffk...@intersessions.com>
To: toaster@shupp.org <toaster@shupp.org>
Sent: Mon Dec 29 23:05:30 2008
Subject: Re: [toaster] Why - Received: from unknown
The receiving mailserver can do reverse DNS perfectly - just doesn't seem
to want to do it during qmail smtp connections. I checked the
/etc/nsswitch.conf file and changed it from:
hosts: files mdns4_minimal [NOTFOUND=return] dns
to:
hosts: dns files
That didn't seem to help either. Do you think a reboot or a service
restart
is necessary after making this change?
At 11:49 PM 12/29/2008, you wrote:
>Jeff Koch wrote:
>>Hi:
>>Does anyone happen to know why all emails received by qmail are
reported
>>as 'Received: from unknown' even though the sending mailserver clearly
>>identifies itself and has reverve DNS setup?
>>Here's a good example from an email I just recieved:
>>Received: from unknown (HELO lists.sourceforge.net) (216.34.181.88)
>
>That suggests the reverse dns lookups are failing on that server.
Have you
>tried some lookups manually to see if they are working? I had an issue
>similar to this just recently with a new server and it took a while to
>realise that I had made a mistake in the nssswitch.conf file and it was
>trying to resolve everything via ldap instead of via dns.
>
>Shane
Best Regards,
Jeff Koch, Intersessions
Best Regards,
Jeff Koch, Intersessions
