librenms-librenms/includes/html/graphs/application/postfix_bytes.inc.php

<?php

$name = 'postfix';
$scale_min = 0;
$colours = 'mixed';
$unit_text = 'Bytes';
$unitlen = 5;
$bigdescrlen = 7;
$smalldescrlen = 7;
$dostack = 0;
$printtotal = 0;
$addarea = 1;
$transparency = 15;

$rrd_filename = Rrd::name($device['hostname'], ['app', $name, $app->app_id]);

if (Rrd::checkRrdExists($rrd_filename)) {
    $rrd_list = [
        [
            'filename' => $rrd_filename,
            'descr'    => 'Received',
            'ds'       => 'bytesr',
            'colour'   => '582A72',
        ],
        [
            'filename' => $rrd_filename,
            'descr'    => 'Delivered',
            'ds'       => 'bytesd',
            'colour'   => '88CC88',
        ],
    ];
} else {
    echo "file missing: $rrd_filename";
}

require 'includes/html/graphs/generic_multi_line_exact_numbers.inc.php';