The only way you will be able to handle large workloads with IIS SMTP 
is to have multiple servers running LISTSERV, set up as DISTRIBUTE 
workers, as described in the IIS SMTP white paper.

For large workloads, I would recommend buying an L-Soft HDMail 
appliance rather than mucking about with IIS SMTP.

-- 
Francoise Becker <[log in to unmask]>

Knowledge is just a click away: http://www.lsoft.com/optin.html