Using TFS 2005 I would like to send an email alert when a build is starting. Getting emails on BuildCompletion works great, just set it using the Team->Alerts. However, I cant find the event for Build Starts. Is this possible in TFS 2005?
I'm pretty sure that there isn't an event that get's raised when a build starts - only when one completes.
The easiest way to do what you want to do therefore is to customise your TFSBuild.proj file so that the first thing that it does is call your custom code (or calls the Mail task in the MSBuild Community Extensions) to send an email.
Another way would be to create a service that polled TFS to get the builds, and then create an email when a new one is started. However the API in TFS2005 isn't well suited for this type of query. I wouldn't really attempt that type of thing below TFS 2008 due to performance concerns, but it might work.
If you want help customising the TFSBuild.proj file then probably best of heading over to StackOverflow as that spills into developer territory - but either way probably more likely to get an answer on that type of question there.