sendmail: sender domain must resolve

[Mathias Körber]

> No, it's the sendmail running on our gateway, smtp.kensingtonlabs.com.

Ok. to be specific:

Does this happen to the client when it talks to smtp.kensingtonlabs.com
(ie the message never even makes in onto that server), or when =
smtp.kensingtonlabs.com
tries sending it to another site?

It might be helpful posting the error messages from the logfile etc
(for one case only).

>=20
> BTW, I've noticed what seem to be one-shot DNS failures on my NT
> workstation running Netscape 4.76 through the Naviscope ad-blocker and
> next-page-prefetch proxy, and wasn't sure if those were coming from =
the
> browser/proxy combination or were real DNS failures. The first click =
on
> some links results in a "site not found" error and a subsequent reload
> of the page successfully pulls the page. This might be related.

Hmm. These sound like od bugs present in Netscape 2 (and early 3s?), but
I never heard of these resurfacing again since. Might be the combo as =
you
say, but that is difficult to figure out w/o more data.