Ganb8te, will you be incommunicado in Tanzania? If not then don't worry about sending a text. But you can if you like. Maybe the "excuse" of him picking up his stuff can be your reason. (funny how this parallels my current situation)
Maybe just say "Hi! I'm off to Tanzania for a week tomorrow. Just wanted to let you know in case you'd like to pick up your box while I'm away. Hope all is well!"
Don't know, maybe someone else has better feedback.
