Im currently working on a system that sends out a large number of monthly newsletters to subscribed users and customers (please note, this is not spam). We send these emails using IIS 6 virtual SMTP server and for the most part, it works well.
However sometimes we must send out 200K+ newsletters- in this case, the IIS6 queue quickly fills up and we are unable to shift them quickly enough. Sending 200K emails may take many many hours, during which time the server is using roughly 2.7mb of the 3mb upload bandwidth we have access to.
I was hoping someone could offer some tips on optimizing IIS 6 for a situation like this, esspecially on some of the server properties such as "limit number of messages per connection" (currently set at 200), "limit number of connections to" (currently at 1000), and "limit number of connections per domain to" (currently set at 100).