Rebol 程式設計/郵件列表規則

MAIL-LIST-RULES 是一個價值物件

   addr-list       none!     none
   addr            none!     none
   opt-cmt         block!    length: 5
   mailbox         block!    length: 11
   maillist        block!    length: 3
   parse-mail-list function! [data [string!]]