FATAL ERROR

Can't locate Mail/CheckUser.pm in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.10.1 /usr/local/share/perl/5.10.1 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.10 /usr/share/perl/5.10 /usr/local/lib/site_perl .) at /usr/www/users/sata/buttrub.com/cgi-bin/fourmeter/fourmeter_link.pl line 548. BEGIN failed--compilation aborted at /usr/www/users/sata/buttrub.com/cgi-bin/fourmeter/fourmeter_link.pl line 548.