Golf mom, Your recent posting brought back many memories of the "mail" situation for me. My xh continued to have his bills sent to my residence until I advised him that he was no longer living here and should have his mail re-routed to his new residence. He ended up w/5 mailing addresses by the time our marriage was over and done with. Your h needs to advise the Post Office and do a change in address form for his mail. It can even be done on line if he doesn't have the inclination to do it in person.
As for the utilities, it may take both of you to change them over to your name. Your h may not have thought about them just yet and you may end up doing them yourself. Time will tell on this.
As for his belongings...some will take only what they think they will need and leave th rest right where they are. If you are sure you are ready to have him take them, then the next time he comes, give him a box of his belongings and continue to do so until he has them all. If you don't, you may very well end up w/them and have to either send them to Good Will or have a very nice yard sale. It's part of their past, and they want no reminders when they first board the Mother Ship. One day, something will click and he'll inquire about something that's been packed away for ages. You have to decide when you want to get rid of his belongings. If they aren't in your way, let them sit...it's your call to make. I was just offering up a solution if they were in your way.
It's a new week and I'm sure you'll be hearing from your "teenager". He can't go very long w/o touching base w/"mom".
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.