The Department of Taxation receives numerous tax returns containing an enclosed "proof of receipt" letter and postage-paid envelope, asking that we return the letter as proof of receipt.  Unfortunately, we do not have the staff to handle this additional work.  If you would like your shipment tracked, we recommend that you use courier services, or mail methods that specialize in mail tracking.  The Department of Taxation is not in the position to acknowledge receipt of packages or shipments outside of standard mail services designed to accomplish this.