Testing Your Mailer Configuration; Diagnosing Troubles With Mail Delivery - Sun Microsystems Sun Workstation 100U System Manager's Manual

System Set-Up and Operation
Sun
100/150
Installation Manual
6.2.3. Testing your Mailer Configuration
The first thing to do is to reboot all the systems whose configuration files you have changed.
Then, send test messages from various machines on the network with a command like this:
hal% /usr/lib/sendmail-v </dev/null addre"e,
hal%
This will send a null message to the specified address, and display messages about what it is
doing. Test that:
• You can send mail to yourself, or other people, on the local machine, by addressing the
message to a plain user name ("root", for example).
• If you have an Ethernet, you can send mail to someone on another machine ("root@hobo,"
for example). Try this in three directions - from the main machine to a subsidiary
machine, vice verla, and from a subsidiary machine to another subsidiary machine, if you
have two. (Note that
I
etcl ho,t,.equiv must be set up on at least the main machine before
this will work. See the subsection, Handling Network Security witla
I
etc/ lao",.equiv and
I .
rho", in the In,talling UNIX lor the Fir" Time chapter.)
• If you have a phone line and you have set up a uucp connection to another host, you can
send mail to someone there and they can send it back (or call you on the phone, if they
receive it). Try having them send mail to you. For example, you could send to
"ucbvax!joe" if you have a connection to ucbvax. Sendmail won't be able to tell you
whether the message really got through - since it just hands it off to uucp for delivery -
so you have to ask a human at the other end. You might be able to get some idea of
what's going on by looking in /u,r/'pool/uucp/LOGFILE; see the Uucp Implementation
De,cription in the Tutorial, section of this manual.
• Mail something to Postmaster on various machines and make sure that it comes to your
usual mailbox, so when other sites send you mail as Postmaster, you're sure you will see it.
6.2.4. Diagnosing Troubles with Mail Delivery
The best tools for diagnosis of mail problems are:
• "Received" lines in the header of the broken message. These give a trace of which systems
the message was relayed through on its way. Note that in the uucp network there are
many sites that do not update these lines, and that in the Arpanet the lines often get rear-
ranged. You can straighten them out by looking at the date and time in each line. Don't
forget to take time zones into account.
• Messages from "MAILER-DAEMON" on various systems. These messages typically report
delivery problems. More and more systems are producing these messages, rather than sim-
ply throwing away mail that they can't deliver.
• The system log, for defivery problems in your group of workstations. Sendmail records
what it is doing all the time, and this information is kept in the system log. In the distri-
buted system, the logs are kept for a week, then discarded. Log files are kept in
/u,r/'pool/log on your network server machine (the system log configuration is taken care
of by the ,etup program during
UNIX
installation - see '1I,'og(S». Today's log is in file '11'-
log; the previous day's is 'lIdog.O; two days' back is '1I,log.l, etc. If you have chronic trou-
ble with mail, look at the log once in a while. At Sun, cron{S) runs a shell script nightly
which searches the log for SYSERR messages and mails any that it finds to "Postmaster".
This way, problems are often fixed before anyone notices them, and the mail system runs
6-12 Revision H of 12 March IQS4