Changing the MOTD
From CyberWurx Customer Wiki
Understanding the MOTD
The MOTD or Message Of The Day is a text file inside the base game directory of your server. It is the first things gamers see when they connect to your server. Post Orange Box gameservers have the capability to point to a single HTML file.
Pre-Orange Box Games
You can use basic HTML in this MOTD as well as plaintext.
<h1>Welcome to my server! Have a good time.</h1> <br> Respect the admins!
Post-Orange Box Games
You can simply put a link to a website that will show up as your MOTD.
http://mywebsite.com/motd.html
Our Left4Dead2 gameservers are equipped with an example motd.txt. If you would like to take a look at the code, here is the site: