YOU'RE INVITED! sent to all Mammoth employees, and, through various channels, everyone on the network:
[a quick note: everyone who is registered on the networks received an invitation with a suitable IC reason attached--maybe they have a relative who works in Mammoth, or they've done work for the company before, etc. You can come up with these on your own; just know that they are (left unstated) IC reasons everyone is invited!]