Suppose you have a problem and you want to report it to an internal mailing list, but you don't know the correct mailing list to use. Here's a trick that apparently is not that well-known, though perhaps that's a reflection on people's lack of creativity than any inherent difficulty in execution.
For example, suppose you have a problem with the file system. One thing you can try is to go to the company Address Book and type "file system" and see what turns up.
Of course, you have to be judicious about this. Some people use this trick but aren't very careful about their search terms, and they end up sending questions to mailing lists like "Windows Team All" which are intended for announcements, not Q&A.
You want to look for a feature-specific discussion group or Q&A group or bug reporting group, not an entire product group.
Use your common sense.
In many cases, you have an idea of a person who might be able to help you. You may know the name of somebody from the file system team because you see their name in status report mail, or you find their name in the change logs, or because they helped you out once before. But, of course, you don't want to go to that person directly, because that would be presumptuous, and they might be on vacation, or they might be busy, or they might not be the right person after all.
But what you can do is look up their entry in the company Address Book, then click on Membership to see what mailing lists they belong to. Browse the list looking for something named "File system bugs" or "File system talk" or "File system automated testing failures" or "File system code reviews", depending on what sort of help you need. If you know more than one person who might help, you can do some set theory to narrow down on a good candidate mailing list to contact.
(Within Microsoft, a common convention is for mailing lists that deal with general Q&A to have "talk" in their name, whereas those that deal with urgent issues have "hot" in their name. And then there is "casual" which is where team members hang out and discuss the latest episode of
Breaking Bad Mad Men Game of Thrones.)
: There is a Microsoft internal Web site called Polyarchy which visualizes organizational data. One of the many things you can do is give it a list of people, and it will show you the mailing lists that they all belong to, thereby doing the set theory magic I alluded to earlier.