From the MSN Postmaster site:
“This site has been developed to give bulk e-mailers/senders, ISPs, e-mail service providers (ESPs), postmasters, and domain administrators a location to learn more about issues and solutions related to sending communications to MSN Hotmail consumers.”
I was amazed at the number of filters (four) a mailing will go through before reaching the recipient’s inbox. The only negative is that this site is really geared for ISPs and ESPs.
eINFO – a collection of articles and case studies about email marketing.