my $alias = Mail::SimpleList::Alias->new(
    Expires  => '7d',
    Auto_add => 0,
    Closed   => 1,
);

# and in Mail::SimpleList::Alias

sub new
{
    my $class = shift;

    bless {
        Owner    => '',
        Auto_add => 1,
        Expires  => 0,
        Closed   => 0,
        @_;
    }, $class;
}