If a mailing list is owned by root sendmail has the same privilages as it does when running as root. If a list is owned by a normally-privilaged user no special privilages are granted. Mailing lists should live in a directory where every path component of which is writable only by root. The list itself should only be writable by the owner. Mailing lists should not be owned by semi-privilaged users.
Sets aliases for users, groups, lists, etc.
An alias file is practiaclly an indispensable tool, but it can harbor dangers other than invalid or misdirected users. Vendors generally no longer ship with a decode alias. But you should check for it's presence. They should also live in a directory where every path component is owned and writable only by root. Semi-privilaged users, such as bin, have authority to run programs without having all the privilages of root.