Re: tlug: External DNS woes

["Scott M. Stone" <sstone@example.com>]

On Thu, 11 May 2000, Stephen J. Turnbull wrote:

> Not really a Linux question, but the biggest concentration of net
> admins/security geeks I know is on TLUG.  And it is making use of my
> Linux box difficult in mail applications.
> 
> I'm having trouble with mail being intermittently refused from various
> sites because "Sender domain must exist."  I believe these are all
> recent sendmail implementations (8.9 or 8.10).  (What does sendmail
> use to make that check, gethostbyaddress()?  Surely not auth.)  It has
> happened with Japanese sites (in particular, TLUG), New Zealand
> (vuw.ac.jp), and US (best.com and lucent.com).  The domain in question
> is my Linux box turnbull.sk.tsukuba.ac.jp.  Its SOA is
> shako.sk.tsukuba.ac.jp.

it looks up the sender domain and figures that an MX record must exist.
Have your sendmail rewrite the outbound headers to appear as
'steve@example.com' or something.  hey, wait, how did you get an
@example.com address??  neat.  Anyway, the remote systems want to see
an MX record for the sender domain, I'm pretty sure.  Or at least an SOA
for it, I think.

--------------------------
Scott M. Stone, CCNA <sstone@example.com>
UNIX Systems and Network Engineer
Taos - The SysAdmin Company 

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