court in a timely fashion. 220 B.R. at 906. Neither the. United States Supreme Court nor the Tenth Circuit has ruled on the issue. d. Proof of Mailing. Before a creditor could invoke the mailbox presumption to show his claim was timely filed, he must introduce sufficient proof of mailing. In Sorrentino v. IRS, 383 F.3d 1187 (10th Cir.2004), the Tenth Circuit discussed the mailbox presumption as it applied to mailing a tax refund to the Internal Revenue Service. A divided panel held it was appropriate to allow the presumption, but only if the proof of mailing included something more than the self-serving testimony of the mailer. The court reasoned: Allegations of mailing are easy to make and hard to disprove. Cf. Benavidez v. City of Albuquerque, 101 F.3d 620, 626 (10th Cir.1996) (<HOLDING>). ■ Because the taxpayer, not the IRS, controls
recognizing difficulty in proving conspiracy recognizing inherently difficult task of proving a negative recognizing that immunity may be waived recognizing that questions of intent and credibility make it difficult to grant summary judgment in favor of the party with the burden of proof recognizing that proving a negative may be difficult