LinuxQuestions.org - mailgraph problem

Hi all,
just installed mailgraph as cgi. The mailgraph daemon fills the dateabase well:

Quote:

root@h10835 : ~ : 12:22
>rrdtool fetch /var/lib/mailgraph/mailgraph.rrd MAX
sent recv bounced rejected

1167132000: 1.6666666667e-02 3.3333333333e-02 0.0000000000e+00 1.6666666667e-02
1167132480: 0.0000000000e+00 3.3333333333e-02 0.0000000000e+00 3.3333333333e-02
1167132960: 0.0000000000e+00 3.3333333333e-02 0.0000000000e+00 1.6666666667e-02
1167133440: 0.0000000000e+00 1.6666666667e-02 0.0000000000e+00 1.6666666667e-02
1167133920: 0.0000000000e+00 3.3333333333e-02 0.0000000000e+00 1.6666666667e-02
1167134400: 0.0000000000e+00 1.6666666667e-02 0.0000000000e+00 1.6666666667e-02
1167134880: 0.0000000000e+00 1.6666666667e-02 0.0000000000e+00 0.0000000000e+00
[...]

But the images produced via mailgraph.cgi only show sent and received mails. There is no entry for error or rejected or anything else. At least rejected messages exist in my mail log and - if I see correct - the rrd database.
To point it out: I don't see an zero entry for rejected emails. There is not even a color for rejected emails in the legend.

What can I do to make them visible in the generated graph?

Thanks a lot,
Clemente