: each_new_port( time = @last_loaded_time ) {|port| .... }
    time: Time
    port: TMail::FilePort

    ᡼ΤߤФƤ꤫ޤ
     time Ϳ줿ȤϤλʹߤ˹줿᡼Ȥߤʤޤ
    Ϳʤä each_mail, reverse_each_mail, each_new_port θ
    줿᡼Ȥߤʤޤ

