While a tied hash would be the easiest way to do this, using your method i see a severe lack of chomping.. obviously a newline thrown on $emailaddr is not going to compare true with $email....

open(RAFFLE_DAT,"< tickets.dat") || die "tickets.dat is not found.";
while (<RAFFLE_DAT>) {
chomp;
($tickennum,$emailaddr) = split(/::/, $_);
if ($emailaddr eq $email) { 
     &bademail();
} else {
     &goodemail();
}
[download]

will probably work as you expect it.