Thanks for the reply falko. I follow tutorial from www.server-world.com
. I'm using Ubuntu 10.04. for the test I use other postfix monitoring like pflogsumm, and it is ok, after I test my server with send some emails, receive email and I can see the log for send, receive, and other postfix log, and this is match with log in /var/log/mail.log. But, on mailgraph for the first graph it's works, the result about send and receive mail same with pflogsumm. And then I test send email again and the output from pflogsumm is correct, But on mailgraph I just see the same graph like the first. I have waiting until 1 hour, But the graph not increase. and I have restart mailgraph and the result is same.
thanks for your help!