...

my $rrd_11            = '/var/lib/mailgraph/mx11/mailgraph.rrd';
my $rrd_12            = '/var/lib/mailgraph/mx12/mailgraph.rrd';
my $rrd_13            = '/var/lib/mailgraph/mx13/mailgraph.rrd';
my $rrd_14            = '/var/lib/mailgraph/mx14/mailgraph.rrd';
my $rrd_virus_11      = '/var/lib/mailgraph/mx11/mailgraph_virus.rrd';
my $rrd_virus_12      = '/var/lib/mailgraph/mx12/mailgraph_virus.rrd';
my $rrd_virus_13      = '/var/lib/mailgraph/mx13/mailgraph_virus.rrd';
my $rrd_virus_14      = '/var/lib/mailgraph/mx14/mailgraph_virus.rrd';
my $rrd_grey_11       = '/var/lib/mailgraph/mx11/mailgraph_grey.rrd';
my $rrd_grey_12       = '/var/lib/mailgraph/mx12/mailgraph_grey.rrd';
my $rrd_grey_13       = '/var/lib/mailgraph/mx13/mailgraph_grey.rrd';
my $rrd_grey_14       = '/var/lib/mailgraph/mx14/mailgraph_grey.rrd';
my $rrd_dane_11       = '/var/lib/mailgraph/mx11/mailgraph_dane.rrd';
my $rrd_dane_12       = '/var/lib/mailgraph/mx12/mailgraph_dane.rrd';
my $rrd_dane_13       = '/var/lib/mailgraph/mx13/mailgraph_dane.rrd';
my $rrd_dane_14       = '/var/lib/mailgraph/mx14/mailgraph_dane.rrd';
my $rrd_dmarc_11      = '/var/lib/mailgraph/mx11/mailgraph_dmarc.rrd';
my $rrd_dmarc_12      = '/var/lib/mailgraph/mx12/mailgraph_dmarc.rrd';
my $rrd_dmarc_13      = '/var/lib/mailgraph/mx13/mailgraph_dmarc.rrd';
my $rrd_dmarc_14      = '/var/lib/mailgraph/mx14/mailgraph_dmarc.rrd';
my $rrd_smtpd_11      = '/var/lib/mailgraph/mx11/mailgraph_smtpd.rrd';
my $rrd_smtpd_12      = '/var/lib/mailgraph/mx12/mailgraph_smtpd.rrd';
my $rrd_smtpd_13      = '/var/lib/mailgraph/mx13/mailgraph_smtpd.rrd';
my $rrd_smtpd_14      = '/var/lib/mailgraph/mx14/mailgraph_smtpd.rrd';
my $rrd_queue_11      = '/var/lib/mailgraph/mx11/mailqueues.rrd';
my $rrd_queue_12      = '/var/lib/mailgraph/mx12/mailqueues.rrd';
my $rrd_queue_13      = '/var/lib/mailgraph/mx13/mailqueues.rrd';
my $rrd_queue_14      = '/var/lib/mailgraph/mx14/mailqueues.rrd';
my $rrd_post_11       = '/var/lib/mailgraph/mx11/mailgraph_post.rrd';
my $rrd_post_12       = '/var/lib/mailgraph/mx12/mailgraph_post.rrd';
my $rrd_post_13       = '/var/lib/mailgraph/mx13/mailgraph_post.rrd';
my $rrd_post_14       = '/var/lib/mailgraph/mx14/mailgraph_post.rrd';

...