Summer residents of Sutton Island have lost their special private postal service, and there may be a moral to the story.

For at least 50 years, residents of the little island, one of the Cranberry Isles off the coast of Mount Desert Island, have been sending and receiving their mail through a trash can that has stood on the float at the Sutton town dock. The can was labeled “U.S. Mail 04662.” That’s the zip code for Northeast Harbor, the nearest post office.

Under an informal arrangement reached long ago, the two dozen or so summer islanders have been chipping in for a modest payment to Beal & Bunker, the ferry service that carries passengers to and from the Cranberries, to deliver Sutton-addressed mail to the trash can and pick up any outgoing mail and take it to the Northeast Harbor post office.

The system worked reasonably well through the years, but there were occasional hitches.

The recent trouble started a few days ago when one of the residents complained to the Northeast Harbor postmaster about a delay in the mail. The postmaster called her supervisor and was told that the trash can service was impractical, insecure, and completely in violation of regulations protecting the U.S. mail.

The U.S. Postal Service’s media relations officer for Maine, Tom Rizzo, soon got on the case. He spoke with the postmaster, with the supervisor, and possibly with some of the Sutton islanders, demonstrating a nice combination of regulatory firmness, compassion for all concerned, and a keen sense of history. He said he understood how the mail arrangement has arisen, at a time long before automated sorting and in a rural area where postmasters knew everybody and tried to keep everybody happy.

But, said Mr. Rizzo, times and technology had changed. Automated mail sorters could not recognize “Sutton Island.” There would be nobody on the island to sign for mail that required a receipt. And there would always be a slight but conceivable possibility of mail theft or even identity theft. He concluded that the old system had to go, like buggy whips and back-porch delivery of milk bottles.

He said there would be no reprimand for the postmaster, who had done no wrong in going along with a system begun long before she took charge of the post office and had done the right thing in reporting the matter to her supervisor. She says the trash can delivery would have been discontinued before long even without a complaint.

The moral, if any, is that you should stop and think before you rock the boat. Everything changes, and you might hustle along that fact of life.