There are more ways to spoof the moderators/owners PLUS an occasional
rotten MTA that spoofs the bounces back to the list.

Thus, if you level of control is extreme, you should consider more
options which include the "OK" mechanism. Frequently mentioned on
LSTOWN-L is the following advice:

http://www.lsoft.com/manuals/1.8d/owner/appendb.html#keySend

In particular, please note:

"When the "Hold" option is enabled (Send= Editor,Hold), the moderator(s)
may approve postings using the "OK" mechanism rather than forwarding the
posts back to the list. "Hold" is valid only with "Editor".

When the "Confirm" option is enabled (e.g., Send=Editor,Confirm), mail
sent by any editor or moderator requires confirmation by that editor or
moderator. This is to prevent a user from forging mail to the list under
an editor's or moderator's return address. The confirmation request is
validated with the "OK" mechanism. Please note that this does not mean
that a double validation is required when an editor approves other
peoples' postings, but only that the editor's own postings to the list
and any reposts he does on others' behalf require a confirmation from him
that he actually submitted them. In other words if the editor simply
"OK"s a posting, he doesn't have to "OK" his own "OK".

It is also possible to set a list to

* Send= Editor,Hold,Confirm

This allows you to "OK" both subscriber submissions and editor/moderator
approvals, as described above."

Pete Weiss @ Penn State