In this case, the taxpayer got a deficiency notice letter from the IRS (90-day letter) and had to file a petition with the court by March 3, 2014. The taxpayer printed a stamp from stamps.com on March 3 and put it on the envelope containing the petition and dropped off the envelope at the post office. The post office affixed a post-mark of March 4 and the IRS claimed that the petition was late based on the USPS post-mark. The court agreed with the IRS based on Treas. Reg. Sec. 301.7502-1(b)(3) which says that the USPS postmark controls when it is combined with a different postmark. Under the facts of the case, the taxpayer actually went to the post-office and mailed the petition certified, but because of long lines, put the envelope in a box and didn't get a hand-stamped receipt. Sanchez v. Comr., T.C. Memo. 2014-223.