In an email campaign, how can I programmatically track deliverability?

Services such as Pivotal Veracity, Email Advisor, and Return Path provide reports of how many messages in an email campaign were routed to the inbox, spam, and junk folders.

We use a system developed in-house to deliver our bi-monthly newsletter, and would like to be able to track how many of our messages are being directed to spam and junk folders.

How can we detect when this occurs? 开发者_如何学JAVA(Note, we'd like to implement this system in-house rather than using an external service)

They don't have a magic algorithm, they analyse how some ISP deal with email... as far as I know, there's no response from the ISP when he receives an email. It doesn't answer the sender with a "spam detected code"