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From: dudek@ubglue.ksr.com (Glen Dudek)
Newsgroups: comp.mail.uucp,comp.unix.questions
Subject: Re: SUN sendmail
Message-ID: <191@ksr.UUCP>
Date: Wed, 4-Nov-87 10:55:25 EST
Article-I.D.: ksr.191
Posted: Wed Nov  4 10:55:25 1987
Date-Received: Sat, 7-Nov-87 11:18:36 EST
References: <315@edsews.UUCP> <918@bdmrrr.bdm.com> <234@bernina.UUCP>
Sender: nobody@ksr.UUCP
Reply-To: dudek@ksr.UUCP (Glen Dudek)
Organization: Kendall Square Research, Cambridge MA
Lines: 61
Keywords: sendmail smail sun
Xref: mnetor comp.mail.uucp:942 comp.unix.questions:4797

In article <234@bernina.UUCP> wyle@ethz.UUCP (Mitchell Wyle) writes:
>All of the suns here are "public;" users go to the nearest un-occupied
>machine to work; the machine=domain naming scheme is therefore not
>acceptable.  What should my sendmail.cf files look like to have one
>central mail server, but let users read their mail from ANY machine?
>

I set up a network of Suns which remote mount /usr/spool/mail from the
master mail server.  This allows users to read their mail from any
machine.  Rather than let mail be delivered to mailboxes on any
machine, I made a one line change to the sendmail.subsidiary.cf
to forward local mail to the central mail server.  This helps avoid
locking problems, and also prevents strange error conditions and
dropped mail if the central mail server is down and a client tries
to deliver mail.  Since the client will try to forward the mail to
the mail server, sendmail will simply queue the mail and retry periodically
until the mail server reboots.

You still need to be careful about mail programs which try to use flock
to lock the mailbox, since flock isn't supported across NFS, but I am
pretty sure Sun mailers do NOT use this.  Emacs and mh and others should
be compiled not to use flock.

Note that this change requires that the master mail host also be the host
which you mount /usr/spool/mail from.

sendmail.subsidiary.cf diffs
-------------------------------
422,423c422,423
< # everything else is a local name
< R$+			$#local $:$1			local names
---
> # everything else is a local name, send to mail host
> R$+			$#$M $@$R $:$1			local names
-------------------------------

I also made a change to sendmail.main.cf so that mail addressed to other
Suns on our network is just delivered locally on the master mail host.
This is just an optimization, since otherwise the master mail host will
send the mail to the client mail host, which will strip its hostname
and send it back to the master.  You should not make this optimization
if you have other SMTP hosts on your ethernet which do not remote mount
/usr/spool/mail from this master.

sendmail.main.cf diffs
-------------------------------
406,407c406,408
< # deliver to known ethernet hosts explicitly specified in our domain
< R$*<@$*$%y.LOCAL>$*	$#ether $@$3 $:$1@$2$3.$D.$U$4	user@etherhost.sun.uucp
---
> # deliver mail for known ethernet hosts explicitly specified in our domain
> #  to us
> R$*<@$*$%y.LOCAL>$*	$@$>30 $1
432c433
< R$*<@$*$%y>$*		$#ether $@$3 $:$1@$2$3$4	user@etherhost
---
> R$*<@$*$%y>$*		$@$>30 $1
-------------------------------

	Glen Dudek
	dudek%ksr.UUCP@harvard.harvard.edu