Is there any compensation or refund in case there is delay in USPS delivery or a returned letter?
No. Once a letter is in the possession of the USPS, Mail A Letter has no control over the delivery. Returned Mail: The United States Post Office will return your letter to Mail A Letter with a general explanation as to why. Mail A Letter will contact you and ask for additional information in order to mail the letter again. The charge is the same price for a second mailing as for the first mailing. If the letter is returned a second time Mail A Letter will notify you that the letter is undeliverable. There is no refund.