On Jul 14, 2005, at 2:40 PM, Darren Evans-Young wrote:

> Is this possible? And if so, how to prevent it?
>
> Listserv receives a posting for a list containing a virus with a
> forged
> MAIL FROM: address. Listserv sends the rejected message back to the
> forged
> address because it isn't subscribed, thereby spreading the virus to
> a new
> email address.

Darren, why don't you check out the F-Secure information on L-Soft's
web site? Listserv and F-Secure have partnered to produce an F-Secure
version that does exactly what you requested. See http://
www.lsoft.com/manuals/f-secure-faq.stm for details.