Where can I join the various Valve mailing lists?
Server Operators and MOD programmers are an important part of Valve's online community. To help them help each other we have set up mailing lists that provide a forum for server administrators and MOD programmers to discuss issues that pertain to running a Half-Life dedicated server or creating a Half-Life MOD. We have also created a mailing list for Valve Dedicated Server release announcements, which is where you will hear first about upcoming Valve Dedicated Server releases and updates.
A complete list (including archives) can be found at http://list.valvesoftware.com/