[rt-users] Re: strange postmaster messages

[Bryan Derman]

Here's a copy of a message I sent to Mac Managers mailing list ... it
looks like it applies to your situation:
---

The Problem (short version)
---
Sending email (ultimately via sendmail) works when running as a normal
user or sudo'd admin/root user, but doesn't work when running via the
real root user (e.g., when run via cron).  The failure resulted from the
email being sent from user at system.domain.com rather than from
user at domain.com, as it was written ... but this only occurred when
sending via real root user.  The failure was always a returned outgoing
email with:

reason: 553 system.domain.com does not exist

which is true because "system" is behind a firewall and is not
DNS-resolvable.


The Solution
---
No one identified the problem, but one person (thanks Joseph) did suggest
sending email directly via sendmail (I'd provided a small /bin/mail-based
script to illustrate the problem).  While that was not a solution, it did
make it easier to troubleshoot, since it was a more direct interaction.

After all too many hours of reading, trying, failing, repeating as
required, I discovered that the solution is rather simple (thus
qualifying it as "normal UNIX configuration"):

I have a very basic sendmail setup (see
http://www.macdevcenter.com/pub/a/mac/2002/09/10/sendmail.html) and only
had to add the following to my sendmail config file, myconfig.mc in my
case (i.e., the ???.mc file used to build the sendmail.cf file, using the
m4 processor):

FEATURE(`domaintable', `hash -o /etc/mail/domaintable')dnl

...then I created the file /etc/mail/domaintable and added the entry:

system.domain.com	domain.com

...then I stopped sendmail, rebuilt the sendmail artifacts, and restarted
sendmail, using the script listed below.  After that, things seem to be
working correctly.

[the good thing about UNIX is that you can do almost anything with it ...
if you have enough time]

Side Note:
---
I'd tried many other features that, according to the sendmail
documentation, would appear to work in this situation.  Among the things
I tried were various incarnations of masquerading features.  I suspect
this is why it worked for all but the real root user.  It's interesting
to note that there's a line of documentation that indicates that this
stuff doesn't apply to the "exposed users," a term for which I couldn't
find a clear definition, but seemed to map to the "trusted users."  I
even tried eliminating the trusted users, but root always seemed to be
mysteriously inserted as a trusted user.  I'm guessing that this is the
reason that none of the other approaches worked (and I think I tried all
other things before trying the domaintable ... yes, I know Murphy quite
well).

I hope this helps save someone else some time.


The script I use to rebuild sendmail:
------
#!/bin/sh

# if NOT using (in myconfig.mc):
# define(`confDONT_BLAME_SENDMAIL', `GroupWritableDirPathSafe')dnl
# then do this (and don't use Apple's "Fix Disk Permissions"):
# chmod go-w / /etc /etc/mail /var /var/spool /var/spool/mqueue

# do this once:
# sudo niutil -create . /locations/sendmail
# sudo niutil -createprop . /locations/sendmail sendmail.cf
/etc/mail/sendmail.cf

# get the template config file once
# sudo cp -p /usr/share/sendmail/conf/cf/generic-darwin.mc
/etc/mail/myconfig.mc
# then make all changes to /etc/mail/myconfig.mc

# prior to running this script, get Admin/root capabilities
# sudo -s

# stop sendmail
#
echo "Stopping mail services"
/usr/bin/killall sendmail
sleep 3

# whenever changes are made, regenerate databases and sendmail config file:
#
for MAP in access domaintable genericstable mailertable virtusertable
do
   if test /etc/mail/${MAP} -nt /etc/mail/${MAP}.db
   then
      echo "Regenerating ${MAP}.db"
      /usr/sbin/makemap hash /etc/mail/${MAP} < /etc/mail/${MAP}
      sleep 1
   fi
done

if test /etc/mail/aliases -nt /etc/mail/aliases.db
then
   echo "Regenerating aliases.db"
   /usr/bin/newaliases
   sleep 1
fi

if test /etc/mail/myconfig.mc -nt /etc/mail/sendmail.cf
then
    echo "Regenerating sendmail.cf"
    /usr/bin/m4 /usr/share/sendmail/conf/m4/cf.m4 /etc/mail/myconfig.mc >
/tmp/sendmail.cf
    sleep 1
    /bin/mv /etc/mail/sendmail.cf /etc/mail/sendmail.cf.previous
    /bin/mv /tmp/sendmail.cf /etc/mail/sendmail.cf
fi

# start sendmail
#
/System/Library/StartupItems/Sendmail/Sendmail start
sleep 3

-- 
bderm at derman.com