I see the suggested way to send tax forms to IRS is registered or certified mail with return receipt required. Local USPS office told me that for return receipt they need someone to do a signature and that's tricky for PO box addresses so they just deliver a slip asking the addressee to come to USPS, sign the return receipt and collect the documents. I know that is not going to work for IRS. Trying to understand how return receipt option works for others. Will asking for a return receipt cause any delay in document delivery if this is true for PO box address.
