I guess you are all familiar with the Out of Office Assistant in Exchange server. Whenever you activate it Exchange will send a messages to anyone who sends you mail that you are out of the office. I never really thought much about the internals of OOF Assistant, but a question from a customer prompted me to do some digging. The question was simply about how often the OOF Assistant would send messages, or Out of Office replies, as they are called. I had no idea and had just assumed that OOF Assistant would send a reply for every message received, but a quick test revealed that that was not the case. It turns out that OOF Assistant maintains a table of all senders sending you mail when the OOF is activated. It will only send an OOF message once to each sender. So if I am away for two weeks and you send me 100 messages (from the same account) you will only receive one OOF messages from me. Neat! More info about this is in this KB article:
Only one reply is sent to each sender when the Out of Office Assistant is enabled (http://support.microsoft.com/kb/157961)
The other day I was joining a Windows 7 RC machine to a domain and I figured I would use my old friend netdom.exe. Netdom has been around since NT and is a command line utility for joining a machine to a domain. It provides some nice extras over the GUI, most notably the ability to specify the OU for the domain account during the join. But Windows 7 just replied ‘netdom.exe’ is not recognized as an internal or external command, operable program og batch file when I typed in netdom.exe. Had Microsoft really removed this great tool?
Yes, they had, but fortunately for us they have given us something better. PowerShell v2 is included in Windows 7 and Windows Server 2008 R2 by default and is no longer an optional component that you can remove or add. It is there permanently. PS v2 has a couple of new cmdlets that perform the same operations that netdom.exe did. Namely Add-Computer which adds a computer to a workgroup or domain (with the ability to specify the OU) and Remove-Computer which removes a machine from a workgroup or domain. Both cmdlets have many parameters making them more than able to replace netdom.exe.
I think this is a great development and hope that all command line tools will be PowerShell cmdlets in the future.
Information wants to be free!