foreach $key (sort(keys %in)) {
    print MAIL "\t", $key, " = \t", $in{$key}, "\n";
    last;
}
close MAIL;

##</code><code>##

my @keys = sort keys %in;
print MAIL "\t", $key[0], " = \t", $in{$key[0]}, "\n";

##</code><code>##

(my $first) = sort keys %in;
print MAIL "\t", $key, " = \t", $in{$key}, "\n";