I am filing my US Taxes forms from Canada and have to mail in the completed tax documents to the IRS. For folks that have done it previously, what mailing service have you used (UPS/FedEx or Canada Post)? I am also trying to figure out the address I should use since IRS considers UPS/FedEx as Private Delivery Service (Link: https://www.irs.gov/filing/submissi...et-addresses-for-private-delivery-service-pds).
