[Mailman-Users] Sendmail and slow sending to large list

Schlachter, Kristofer kschlachter at burlybear.com
Thu Aug 30 18:28:30 CEST 2001


Thanks for replying. I hope that I didn't write too much.

Some more info:
I have a cabinet at a co-location facility(Globix) where I host a website.  
I have a firewall(managed by ISS) in my cabinet and the all my machines are
behind it.  
I am using Globix's dns servers which are on the other side of my firewall.
I should mention that currently the mailman server does not have an mx
record. It will eventually, but I am only sending mail out to a group of
people who subscribed to a newsletter.  They can unsubscribe through a web
page. How bad is this for performance?

> Kristofer, 
> Your problem could be the reverse look ups that the server is trying to
> do. If you add the machines to the /etc/hosts files and configure the
> /etc/nsswitch.conf to do files before dns that should clear 
> up that problem.
I am using public IP's for all my machines, is it still possible that this
could be a problem?

> The other problem... Let me get this straight. The mailman server is
> sitting behind the firewall and the dns server is on the 
> other side? 
That is correct.  

> What is blocking the port? The firewall or the DNS server.

> can you route the mail to antohre machine that you can use as a smarthost?
I don't know what smarthost is.  Would putting BIND on the mailman machine
be a good idea?  I am thinking about it.

> Give me a better idea on the layout of the firewall, dns server and
mailman server.
The rulebase on my firewall(A managed firewall running Checkpoint Firewall-1
on Nokia Hardware)allows the mailman to talk to the dns servers on port 53
with udp and tcp packets.  The rule only goes one way: from the mailman
server to the dns server.  I think that there is something wrong with my
setup though.  I keep getting lots of dropped packets from the dns server
trying to talk to my mailman server on ports in the 1000-5000 range
ascending by one port each try.  That shouldn't happen as the firewall
should be aware of what ports my mailman server used to connect with(I


Kristofer Schlachter

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