First and foremost... ask if you can bring a radio onboard before even thinking about any of this. Their radio operator will probably notice your operations.

Second, the Sailmail service doesn't even require an amateur radio license. It works over commercial frequencies.

http://www.sailmail.com/smprimer.htm#Getting%20Connected%20via%20Radio

Third, the modem required for Sailmail is several hundred dollars, not counting the radio and the antenna (another thousand plus)...

"Blizzard understands end game progression"

Yeah, only if you like standing around looking for groups for hours and hours on end between "Tier 1" 5-mans and everything else.