These two characters go on to exchange several encrypted messages using this system.
It was known that they exchanged messages with the ground.
Over the next month or so they exchanged occasional friendly e-mail messages and phone calls.
Within 48 hours they had exchanged numerous messages and spoken on the phone.
They can immediately exchange messages and, if there is mutual interest, decide where to meet.
They exchanged messages, then reduced speed to let the convoy past them.
Earlier this month, the panel exchanged e-mail messages over one week.
Each business process consists of two or more subjects which exchange messages.
They are not permitted to exchange messages with the outside world, which presumably includes e-mail.