Read the USPS reason on the returned piece before you change a customer record or mail again. "Not known," "insufficient address," "refused" and "unclaimed" each call for a different next step.
Reviewed October 17, 2026
Start with the words on the returned piece
Attempted—Not Known: USPS tried to deliver, and the addressee is not known at that address. USPS: nondelivery endorsements It does not tell you where the customer lives now.
Insufficient Address: the address is missing parts, and the correct address is not known. USPS: Insufficient Address Look for the missing piece. Do not decide the customer refused the notice.
Refused: the addressee declined the mail or the postage charge. USPS: Refused
Unclaimed: the addressee abandoned the mail or did not call for it. USPS: Unclaimed Keep that separate from a refusal when you review the return.
Set the next step without guessing
We suggest keeping the returned envelope and writing down its exact wording. Have someone in your office verify the account and the address before you correct anything. Keep the USPS reason apart from what you find later.
For a refusal, or a recipient question you cannot settle, ask the person who runs your warning procedure what to do. Do not mark an account warned, closed or corrected just because a return was logged.
File the returned envelope, its exact USPS wording and your account review with the mailing job. See what Duty to Warn mailing records to keep for the rest of that file.
Suggested review-owner and follow-up record
- Name the office reviewer and record the date the return reached your office.
- Note the account and address checked, what the reviewer found and where the returned envelope is filed.
- Record the next step agreed under your warning procedure, who owns it and when they will review it. Add the outcome to the same mailing-job file.
Is a returned envelope proof the customer rejected the safety message?
Not by itself. Start with the exact USPS wording. A missing address element and an unclaimed piece are different events. Even "Refused" means the addressee declined the mail. It does not tell you what anyone read or understood.
Ask your mailing provider who receives returns and how your office gets them. Put that in the job scope before release.
General information, not legal advice. Talk to your own attorney or insurer about what your company must do when a notice comes back.
Get a Duty to Warn quote and ask how returned pieces will reach your office.
About Bill Stomp
Bill Stomp built Propane Safety Pro. He is a war veteran who ran over 87 propane branch offices across 12 states, and he has helped more than 200 propane companies improve their profits, sales, safety and operations.