Does your internal DNS server have entries for the windows machines?  Does the
RH7.2 client have a domain name that it passes to the RH7.1 server that matches
a relaying rule for sendmail?  Just because you have BIND running on the RH7.1
machine doesn't mean that the IP addresses it's handing out are also being given
a DNS entry.

What entries does BIND have for your local machines?  what rules is sendmail
running with, with regard to relaying?

> But, when it does DNS lookup shouldn't it get passed, as it is doing the
> lookup against my local server, which is an authoritative server for my
> local domain. The strangest thing is, when I use sylpheed it gets
> through without any problems.
> 
> Sundar
> 
> Kevin Brown wrote:
> 
> >I would suspect that the sendmail server is doing a DNS lookup of your host and
> >since it is a 192.168.x.x address it isn't in the DNS server and it has relaying
> >turned off (this is a good thing).  You might need to add a rule to sendmail to
> >allow it to relay mail from 192.168.x.x addresses, preferably only accepted on
> >the internal LAN interface.
> >
> >>I have been having this problem for quite sometime.That is, whenever I
> >>reply to a mail from Outlook Express, I get the following error
> >>
> >>The message could not be sent because one of the recipients was rejected by
> >>the server. The rejected e-mail address was 'plug-
> >>discuss@lists.plug.phoenix.az.us'. Subject 'Re: Adding a third IDE drive in
> >>Linux', Account: 'mail.esaravana.com linux', Server: 'mail.esaravana.com',
> >>Protocol: SMTP, Server Response: '550 5.7.1 <plug-
> >>discuss@lists.plug.phoenix.az.us>... Relaying denied. IP name lookup failed
> >>[192.168.0.83]', Port: 25, Secure(SSL): No, Server Error: 550, Error
> >>Number: 0x800CCC79
> >>
> >>The server it is trying to connect to is a RedHat 7.1, sendmail and a Bind
> >>9 DNS, which also gives all my home computers IP address through DHCP
> >>Protocal.
> >>
> >>It's not a problem, when I use sylpheed from RedHat 7.2 client.
> >>
> >>Any help is appreciated.
> >>
> >>Sundar
> >>
> >>________________________________________________
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> >>
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> >>
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> >
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> >
> 
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