>Number:         31369
>Category:       bin
>Synopsis:       sendmail default configuration sensitive to DNS misconfigurations
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Sep 22 09:18:00 +0000 2005
>Originator:     Christian Hattemer
>Release:        3.0_BETA
>Organization:
>Environment:
NetBSD lahksa.t-link.de 3.0_BETA NetBSD 3.0_BETA (SPARC-TEST) #0: Wed Jun 15 16:21:50 CEST 2005
>Description:
[This PR was pasted together from some of my mails to netbsd-users@ in early
september.]

Everything was fine, until lately the name "localhost.myisp.de" appeared in
DNS with a valid external IP. Since that sendmail tries to relay local mail
(e.g. reports from /etc/daily) via "localhost.myisp.de". It seems the name is
built from my hostname "mybox.myisp.de" by taking "localhost" and appending
the hostname minus the first part.

Quite early I found the suggestion to put

FEATURE(`msp', `[127.0.0.1]')dnl

into submit.mc.

I looked there and it contained already that line. So I thought the problem
must be somewhere else. However it turned out that submit.mc isn't used and
that netbsd-msp.mc is used instead. That file reads

FEATURE(`msp', `[localhost.]')dnl

After I had changed that file as suggested above, generated a new submit.cf
from it and restarted sendmail it's working again, even with the still
broken DNS config of the ISP regarding localhost.

>How-To-Repeat:
See above.
>Fix:
* Change src/gnu/usr.sbin/sendmail/cf/cf/netbsd-msp.mc to use 127.0.0.1 as
  shown above.

* Remove src/gnu/dist/sendmail/cf/cf/submit.mc and (or at least) the logic
  that installs it into /usr/share/sendmail/cf to avoid future confusion
  about its relevance.