Written by Kaye S.
Emails to a deployed sub are possible only when it surfaces to communication depths.
Reasons friends/family might not hear from their sailor:
1. work is heavy at sea, 2. new sailors ("nubs") don't get down time, 3. limited access to onboard computers, 4. the sub is running "dark" (i.e. silent) or 5. other reasons covered in the document below.
Try not to get discouraged... it's amazing to have this ability, compared to only a few years ago!
This PDF document: Sailor Mail Process explains the process more fully and gives precise directions for how you should format your message.