On 10 Jul 00, at 11:18, Mark Hunnibell <[log in to unmask]> wrote:

> I there a way to configure a list so that the POSTACK1 message is only sent
> to someone if they are not on the list?

Not exactly, but you could set up the list as semi-moderated, i.e.,
Send=Editor,Hold [log in to unmask],(listname)
and edit the POST_EDITOR template to contain the text of the current
POSTACK1.

This has the additional benefit/drawback (depending on how you look
at it) that the primary editor has to approve non-subscriber posts
before they can get posted to the list.

Francoise