#!/bin/sh
# smtp-qstats: show the number of things left in the queue
#
if [ -x "/usr/bin/mailq" ]
then
  exec mailq -OMaxQueueRunSize=0 | tail -1 | cut -d ' ' -f 3
  exec mailq | grep -c "[[:space:]]\{6\}<"
fi

Which returns number of items in the mailq on line 1 and number of recipients on line 2. Next add a line in inetd.conf:

smtp-qstat      stream tcp nowait root /root/scripts/smtp-qstat

(I define smtp-qstat and some other management ports in /etc/services on all servers)

Then on the mrtg machine, I have this qstat.pl script:

#!/usr/bin/perl 
# this script relies on port 7777 of mailserver returning qlength
use strict;
use Socket;
my (@remotes, $port);
@remotes = ("in-server","out-server");
$port = "7777"; #smtp-qstats

# Straight out of the blue Camel - pp. 349
my ($iaddr, $paddr, $proto, $line);
my @num;
@num = (0,0);
my $index = 0;
my $mx;
foreach $mx (@remotes) {
        $iaddr = inet_aton($mx) or die "no host: $mx";
        $paddr = sockaddr_in($port, $iaddr);
        $proto = getprotobyname ('tcp');

        socket (SOCK, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
        connect (SOCK, $paddr) or die "connect: $!";

        # munge the data
        while () {
                if ($_ =~ /(\d+)$/) {
                $num[$index] = $1;
                }
        } 
close (SOCK) or die "close: $!";
$index++;
}
# print the data for suitable for mrtg
print "$num[0]\n$num[1]\n1\n$remotes[0]\n";

The script takes the qstat from the outbound and inbound mail servers and formats the number the way mrtg likes.

Then add this in your /etc/mrtg.conf

Title[qmail]: Mail
Options[qmail]: gauge,growright,noinfo
YLegend[qmail]: emails
LegendI[qmail]: inbound
LegendO[qmail]: outbound
Legend1[qmail]: inbound queue entries
Legend2[qmail]: outbound queue entries
Legend3[qmail]: max inbound queue 5m
Legend4[qmail]: max outbound queue 5m
Target[qmail]: `/root/qstats.pl`
SetEnv[qmail]: MRTG_INT_IP="" MRTG_INT_DESCR="qmail"
Directory[qmail]: qmail
MaxBytes[qmail]: 50000
XSize[qmail]:340
YSize[qmail]:120
PageTop[qmail]: <H1>Mail Queues</H1>
 <TABLE>
   <TR^gt;<TD>System:</TD>     <TD>Queues</TD></TR>
   <TR><TD>Description:</TD><TD>Mail Queue size</TD></TR>
 </TABLE>

Presto - instant mailq monitoring! One day I saw the queue heading for 2000, I tracked it down to one of the tech who had forwarded all his mail to yahoo, where he was forwarding it back.

So, instead of it only getting fixed when you happen to be around a browser and checking the graphs, you can get a message on your cell phone any time of the day or night, if you so desire. It allows you to be much more proactive to your boss' love-letter log-jam.

Sean

Long ago I learn to rate my todo list items with "effort" and "looks" factors. Do one high-looks item for the boss, one hard one to make real progress.

Have you looked at the postfix address verification support? It's described in http://www.postfix.org/ADDRESS_VERIFICATION_README.html

Sean