One way to do it.
open(FILE, $infile) || die "Can't open $infile for read";
@data = <FILE>; close(FILE);
open(FILE, ">$outfile") || die "Can't open $outfile for write";
foreach (@data) {
if($_ =~ /\@/) {
($junk, $email) = split(/=/, $_);
print FILE $email;
}
}
close(FILE);