Index: plugins/node.d/postfix_mailvolume.in
--- plugins/node.d/postfix_mailvolume.in.orig
+++ plugins/node.d/postfix_mailvolume.in
@@ -65,7 +65,7 @@ my %expired_queue_ids = ();
 use constant queue_id_expiry => 6 * 3600;
 
 my $LOGDIR  = $ENV{'logdir'}  || '/var/log';
-my $LOGFILE = $ENV{'logfile'} || 'syslog';
+my $LOGFILE = $ENV{'logfile'} || 'maillog';
 
 
 sub parseLogfile {
