[thechat] Re: Returned mail: User unknown

William Anderson neuro at well.com
Thu Apr 26 16:07:58 CDT 2001

----- Original Message -----
From: "Daniel J. Cody" <djc at starkmedia.com>
To: <thechat at lists.evolt.org>
Sent: Thursday, April 26, 2001 9:14 PM
Subject: Re: [thechat] Re: Returned mail: User unknown

> < precursor >
> didnt mean to come off like an asshole before william.. i was cranky and
> hungover this mornign :)

hey no probs - i was dealing with helpdesk crap today, and just got pissed
at messages being bounced for no discernable reason

> William Anderson wrote:
> > > get whatever NAT box you're using to stop sending its *PRIVATE*
> > > IP address first off.
> >
> > the IP address that will be presented by our firewall is a real life
> > external IP address.
> [djc at leo djc]$ nslookup wpanderson.wsatkins.co.uk
> Server:  ns1.starkmedia.com
> Address:
> *** ns1.starkmedia.com can't find wpanderson.wsatkins.co.uk:
> Non-existent host/domain

yep, you'll never find that DNS resolution, as it only exists as a reverse
DNS entry for my workstations IP address at the office ( -
blatantly internal and not routable to from the outside world).

however, my workstation and 16,000 other workstations and servers all appear
to the outside world as (which should resolve to
wsatkins.co.uk).  This is usually good enough for most purposes.

> it may have a real external IP address, but 20 bux says you have it
> configured so that the box itself equates wpanderson.wsatkins.co.uk to
> its *internal* address, which is why thats showing in the mail headers

as I mentioned, not quite, but the bottom line is I'll bet 20 bux that it's
nothing to do with me being behind a firewall (I won't say which one for
obvious security reasons!).

It _could_ be that our 2 Mb connection to the outside world is almost always
saturated 9-5 UK time, and leo just can't deal with the possibly and
occasionally latent SMTP connection.  I have a similar config at home
(workstation with 192.168.x.x address behind a firewall - SmoothWall, btw -
with outward SMTP delivery being handled by a machine on my LAN as opposed
to using the ISP SMTP) and haven't had these problems with mailing

nb: the reason I hid my work firewall identity and disclosed my home
firewall identity is that I work on the SmoothWall project in my spare time,
and I eat our own dog food.  If you have a spare 386/486/Pentium or other
Intel PC class box with some ethernet cards and cables, you can build a
secure firewall for your LAN in minutes :)  Part of the work I did was the
website - http://www.smoothwall.org/ - feel free to critique - I've probably
done sooo many things the wrong way ;)

> anyways.. i hope to have it worked out soon.. looks like we've got
> enough money together to buy a new webserver for evolt, and i'll config
> that as a backup for l.e.o

don't bust your wallet on my account, but if it helps then I'm all for it :>

  ___  ___ __ _________ @well.com  William Anderson - www.well.com/~neuro
 / _ \/ -_) // / __/ _ \|  "Oh, God! If you want something done properly,
/_//_/\__/\_,_/_/  \___/|  kill Baldrick before you start!" -- Blackadder

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