is(scalar(@x), 2, 'augmented mboxo');
is($x[0], $cmp, 'original message preserved');
is($x[1], $buf . "\nx\n", 'new message appended');
is(scalar(@x), 2, 'augmented mboxo');
is($x[0], $cmp, 'original message preserved');
is($x[1], $buf . "\nx\n", 'new message appended');