diff --git a/plugins/node.d/postfix_mailvolume b/plugins/node.d/postfix_mailvolume
index 95a3b4d97..e9e60f939 100644
--- a/plugins/node.d/postfix_mailvolume
+++ b/plugins/node.d/postfix_mailvolume
@@ -191,7 +191,7 @@ if ( $ARGV[0] and $ARGV[0] eq "config" ) {
     print "graph_args --base 1000 -l 0\n";
     print "graph_vlabel bytes / \${graph_period}\n";
     print "graph_scale yes\n";
-    print "graph_category postfix\n";
+    print "graph_category mail\n";
     print "volume.label delivered volume\n";
     print "volume.type DERIVE\n";
     print "volume.min 0\n";