The IRS does not seem to like the USPS, at least all of the time. But it does seem to like DHL and FedEx a little more lately, now it says that the timely use of private services will be evidence of timely delivery of returns. This while Express Mail and Priority Mail services offered by the U.S. Post Office still will not qualify.
But, as in the past, the Revenue Service will still recognize registered or certified mail is an additional way a filer can prove that tax forms were actually delivered to the agency when the time of filing is in