If correspondence is properly addressed to the USPTO pursuant to 37 C.F.R. §2.190 (see TMEP §305.01) and deposited with sufficient postage in the Priority Mail Express® Post Office to Addressee service of the USPS, but not received by the USPTO, the party who submitted the correspondence may file a petition to the Director under 37 C.F.R. §2.146(a)(2) to consider the correspondence filed in the USPTO on the USPS deposit date. 37 C.F.R. §2.146(e).

The petition must:

1. (1) Be filed within two months after the date of deposit;
2. (2) Include a copy of the previously mailed correspondence showing the number of the Priority Mail Express® mailing label thereon; and
3. (3) Include a verified statement attesting to the facts of the original mailing.

37 C.F.R. §2.198(e)(1)-(3).