RE: Weird relay problem.

[Dan Didier <Dan@xxxxxxxxxxx>]

Martin,

I have the same problem occuring on a few of my qmail installs which use
different DNS servers.  I believe that there is some sort of issue with the
service providers DNS.  I have not had any issues up until recently, and I
have had the problem in more than one location.  

To solve this problem, you can turn reverse DNS lookups off - everything
will work just peachy after you do that.  I am not happy with that solution,
as I would like to know the problem, but other people have mentioned this
issue on the qmail list before (about 2 weeks ago) and they were not taken
very seriously.  Nothing changed on my end, but something weird was
happening with the service providers DNS, (Road Runner was one of them,
Choice One was another) to fix it follow the instructions in seciton G.10 of
the life with qmail faq http://www.lifewithqmail.org/lwq.html#smtp-slow

This will turn reverse-DNS lookups off, and your qmail smtp functionality
will be back!

Dan

> -----Original Message-----
> From: Martin Hicks [mailto:mort@bork.org]
> Sent: Sunday, March 03, 2002 3:30 PM
> To: qmail@list.cr.yp.to
> Subject: Weird relay problem.
> 
> 
> 
> My qmail machine seems to be doing very strange things in the 
> last couple days.
> The setup is a qmail mailserver running on linux-x86, which 
> is also acting 
> as my router/firewall.  The machine is delivering mail just 
> fine, as it has
> been doing for a number of years.
> 
> The problem is that recently, in the last week or so, it 
> doesn't seem to want
> to allow SMTP connections from the "inside" network.  DNS is 
> properly configured,
> and I can POP mail off the machine using fetchmail.  My 
> desktop machine, which
> is behind the firewall, is using exim which simply relays 
> mail to the qmail
> machine.  The qmail machine is not delivering the mail though, and the
> mail just sits in the exim queue on my desktop box.
> 
> I can see the TCP connection in netstat, but there is no 
> mention in the 
> logs on the qmail machine about any mail delivery.  The exim client 
> eventually gives up with "TCP connection timed out".
> 
> Switching the relay host on my desktop to another smtp server and
> running the queue manually flushes the queue immediately.  
> 
> I am observing the same problem on another machine with mozilla mail,
> while using the qmail machine as the SMTP server.  Again, switching
> the SMTP server to another one fixes the problem.  This solidifies
> my belief that it is the qmail machine that is broken.
> 
> Qmail-1.03 on Debian Woody Machine.
> Using tcpserver.
> 
> mort@galileo:~$ cat /etc/tcp.smtp
> 127.0.0.1:allow,RELAYCLIENT=""
> 192.168.69.1:allow,RELAYCLIENT=""
> 192.168.69.2:allow,RELAYCLIENT=""
> 192.168.69.9:allow,RELAYCLIENT=""
> 
> 
> any help would be appreciated.
> 
> -- 
> Martin Hicks   || mort@bork.org    
> Use PGP/GnuPG  || DSS PGP Key: 0x4C7F2BEE  
> Beer: So much more than just a breakfast drink.
>