All of our regularly recurring bills are e-billed, then automatically debited on their due date from our checking account. This has been an efficient and worry-free process and seems to be the best way to handle these.
We had a box at UPS for forwarded mail our first year of retirement. We could call them and have them send the contents to the campground of our choice, which was a nightmare. Priority mail could take many days, a week or more, to rural areas.
My son now receives forwarded, first-class mail, and reviews/scans/sends on to us anything that is needed. We can then mail a check or use bill-pay through our bank. Everything else is held until we return. No problems.
We did once meet a couple on a ferry somewhere, he was a retired physician who was terrified of using the internet for e-bills, automatic debit, etc. When they traveled for months at a time, he flew home once a month or so to check the mail and handle things that had come in.