I can initiate an SMS message from the InReach. Others cannot initiate a message to my InReach; they must reply to an existing message sent by me. Sometimes, to remind them, I send them a new message to store just before I leave on a trip. Only four people have my InReach stored message, and I am pretty sure that they all understand because all of them are family and are backcountry campers/hikers themselves.
If I have a cell signal, I can text these folks instead of using the InReach.
I cannot remember where I hit on this stored message idea. Don't think it was in the owner's manual. Maybe on a forum somewhere? Or just a way I thought of myself to get around the issues?
The pack clip is part of the InReach, already attached onto the back upon arrival and apparently not detachable. It looks like it could slide onto a belt or a pack strap. I have never used this clip. There is also a cord lanyard which can be used to wear the InReach around your neck or someplace.
When I have dealt with customer service (by e-mail), their replies have been prompt, courteous, concise, and complete. I am satisfied.