my $from = '<>';
my $to   = '<>';

if (!$from || !$to || $from eq "<>"   || $to eq "<>"  ) {print "Ok 1\n"}
if (!$from || !$to || $from =~ /^<>$/ || $to =~ /^<>$/) {print "Ok 2\n"}

__END__
Prints:
Ok 1
Ok 2