def parse_comment(raw)
      c = nil
      if raw =~ /\A\((.+?)\)(.+)\z/
        c, raw = [$2, $1]
      end
      if raw =~ /\A(.+)\((.+?)\)\z/
        raw, c = [$1, $2]
      end
      [raw, c]
    end
def parse_comment(raw)
      c = nil
      if raw =~ /\A\((.+?)\)(.+)\z/
        c, raw = [$2, $1]
      end
      if raw =~ /\A(.+)\((.+?)\)\z/
        raw, c = [$1, $2]
      end
      [raw, c]
    end
"(comment)mailbox" or "mailbox(comment)", only one comment
 RFC Doesn't say what to do if 2 comments occur, so last wins