SUMMARY: sendmail 8.9.1 problems (NIS, DNS)

From: Stefan Voss (
Date: Tue Feb 16 1999 - 03:00:48 CST


first, I would like to thank the following people for their immediate help:

    Klorese, Roger B.A. <>
    Ray Delaney <>
    Martin D. Baldenegro (RRNC) <>
    Marco Greene <>
    Ken Farmer <>
    Chad Price <>
    Ray Delaney <>

and in particular

    Bismark Espinoza <>
    Anvar Bagautdinov <Anvar.Bagautdinov@Sun-Center.Nsk.SU>

who gave the most useful input.

2 of my 3 problems are solved!

1. name server lookups, 2. problems with certain e-mail adresses:

1. It turned out, that my /etc/aliases file was wrong. The entries for me
   looked like this:

      s.voss: stefan
      stefan: stefan@HOSTNAME

   Changing this to:

      s.voss: stefan


2. I had to change my /etc/resolv.conf to this:


   Note, that the entry "order" is kicked off (the search order is maintained
   by /etc/nsswitch.conf), and that "domain" was changed to "search".

3. In /etc/nsswitch.conf, I changed the entry for hosts to this:

      hosts: nis dns

   I tried that before, but it did not work, probably because of the wrong
   alias file and the wrong resolv.conf.

One of the friendly helpers suggested, that "It sounds like your ISP does not
have an MX record defined for" I'm sure, they have, because (1) they
are one of the leading providers in germany, and (2) the same adress works fine
with sendmail 8.8.5 - the problem was not with the ISP, but with my

Another one suggested running a caching only server to speed up name lookups -
sounds like a good idea. I will think about that, although this is not the
problem for mail which is destined to leave our domain, it doesn't matter
whether such a lookup takes 1 second or 5 in this case.

3. NIS:

But one problem persists: my NIS master (which is still SunOS 4.1.3) supports a
map "mail.aliases" but not "aliases.nis". After I put the Solaris 2.5.1 NIS
client in NIS compatibility mode, sendmail did not complain any longer about the
unknown map. However, it does't care a bit for the contents of "mail.aliases" -
when I send mail to a a user XXX which is an alias pointing to me, a file
/var/spool/mail/XXX is created.

However, if I don't manage this, this will be no problem, because we have only
one mail server, and all people will run their mail tool on this machine (and
maybe a second machine if I overload the machine), so maintaining a local file
will not introduce much administrative overhead compared with maintaining one
NIS map.


-- ORIGINAL POSTING: ----------------------------------------------------------

Hi list,

System: Solaris 2.5.1 HW 11/97 (SunOS isis 5.5.1 Generic_103640-12 sun4m
          sparc SUNW,SPARCstation-10)

sendmail: 8.9.1, compiled with NIS and NEWDB support

1. When sending a mail locally inside our company, sendmail generates a name
   server request. tcpdump doesn't show which name is looked up, unfortunately,
   and I have not installed snoop.

      10:16:29.920024 isis.53147 > 42766+ (34) (DF)
      10:16:29.920024 isis.53147 > 42766+ (34) (DF)
      10:16:32.110024 > isis.53147: 42766* 0/1/0 (112)

   We don't have our own DNS server (that would be a bit oversized for a com-
   pany like ours).

   Our ISP says, that the name of the mail server must be present in /etc/
   hosts. This is the case (of course, otherwise, I would have severe trouble),
   but he has no experience with NIS or Solaris - they use LINUX (not bad, but
   useless for me...). So I can't expect useful input from there and hence I
   count on the collected wisdom of this list.

   However, this name server request costs money. Our ISP says, that sendmail
   needs to do this in order to check for correct adresses and prevent
   relaying. Is this true ? Or can I stop this ? And how ?

2. When I send a mail to or ISP (e.g., I get the mail back:

> The original message was received at Wed, 10 Feb 1999 12:18:23 +0100 (MET)
> from
> ----- The following addresses had permanent fatal errors -----
> ----- Transcript of session follows -----
> 550 Host unknown (Name server: host not found)

   Syslog shows this:

   Feb 10 12:18:26 isis sendmail[1933]: MAA01931:,
ctladdr=stefan (520/10), delay=00:00:03, xdelay=00:00:00, mailer=esmtp,, stat=Host unknown (Name server: host not found)

   When I send mail to, it works fine.

   The difference is: is just a domain name, but hannover.geoquest. is a host name (which can be verified with traceroute).

   This is my /etc/resolv.conf:

      order local, nis, bind

   This is my /etc/nsswitch.conf:

      passwd: files nis
      group: files nis
      hosts: nis [NOTFOUND=return] files
      networks: nis [NOTFOUND=return] files
      protocols: nis [NOTFOUND=return] files
      rpc: nis [NOTFOUND=return] files
      ethers: nis [NOTFOUND=return] files
      netmasks: nis [NOTFOUND=return] files
      bootparams: nis [NOTFOUND=return] files
      publickey: nis [NOTFOUND=return] files
      netgroup: nis
      automount: files nis
      aliases: files
      services: files nis
      sendmailvars: files

3. Using "aliases: files nis" in /etc/nsswitch.conf did not work, syslog
   reported this:

   /var/log/syslog.6:Dec 16 10:31:09 isis sendmail[274]: NOQUEUE: SYSERR(root):
   Switch map aliases: unknown member map aliases.nis: No such file or

   So I had to use only "aliases: files" (as you can see above). What am I
   doing wrong ?

   Our NIS master is (still) SunOS 4.1.3


                                     (o o)

  Stefan Voss Phone: 0049 / (0)5130-9775-51
  System and Network Administration Fax: 0049 / (0)5130-9775-10
  TerraData Geophysical Services GmbH e-mail:
  Zoellners Garten 1
  D - 30900 Wedemark/Bissendorf, Germany

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