Iowa Admin. Code r. 591-17.13
17.13(5) Proof of mailing. Proof of mailing includes either: a legible United States postal service postmark on the envelope, a certificate of service, a notarized affidavit, or a certification in substantially the following form:
| I certify under penalty of perjury and pursuant to the laws of Iowa that, on [date of mailing], I mailed copies of [describe document] addressed to the [agency office & address] and to the names and addresses of the parties listed below by depositing the same in [a United States post office mailbox with correct postage properly affixed or State interoffice mail.] | ||
| [Date] | [Signature] |