During the first two weeks of recruit training, recruits will send home a letter stating they've made it to MCRD San Diego and will provide an address for which to receive mail.
Here's is an example for recruit mail:
Recruit John E. Doe
1st BN, Alpha Co. PLT _ _ _ _
39001 Midway Ave
San Diego, CA 92140-(plus platoon #)
*IMPORTANT NOTE: All mail is routed through the only mail office on the depot. What is critical, to have your mail reach your recruit, is to ENSURE YOU LIST THE CORRECT TRAINING COMPANY AND PLATOON. The mail office will see that information and sort the mail to that company and platoon. The company and platoon information will be listed on the letter your recruit sends home about 2 - 3 weeks into training.
If a message is required to notify a recruit of an emergency situation at any time during recruit training, please contact your local America Red Cross or please visit the American Red Cross Emergency Communication Services web page, to have an official message sent to MCRD, San Diego. In order to process the message quickly, please provide the recruit's name, social security number, company and platoon.