I just read on http://www.e2ksecurity.com/ (Paul Robichaux blog) that the CIS Benchmark for Exchange 2003 document has been released. It covers how to harden an Exchange 2003 server environment.
http://www.cisecurity.org/bench_exchange.html
Day to day happenings of a messaging admin. I'll discuss best practices, problems, and resolutions that I come across as I work with Active Directory, Exchange 2007, Exchange 2003, Office Communications Server, clusters, Archiving Products, and SMTP gateways.