As part of my ramp-up for Exchange Connections in April, I’ve been working on my slide deck for Sender ID. I’ve got the slide deck written; now I need to run through it and polish the presentation.

One of the interesting pieces of information I came across concerns a bug in the Sender ID implementation in Exchange Server 2003 SP2. (As an aside, I love the Exchange community. A very kind gentleman by the name of Mike Ruman saw that I will be doing a session on Sender ID and sent email to Paul to let us know about this issue.) At the time he sent me the information, a hotfix was available but the KB article wasn’t yet available. As of February 1st, Microsoft published KB 910272, “The ‘Sender ID Filtering’ feature does not work correctly in an Exchange Server 2003 SP2 server.” If you’re using Sender ID on Exchange Server 2003, you should install this hotfix.

From the details I was given, this bug manifests when your policy uses the – (Fail) mechanism prefix combined with a reference to another domain. According to the KB, it can result both in false positives and false negatives, so this should probably be considered a mandatory hotfix for Sender ID.