Iowa Code § 633.40: Notice in probate proceedings.

1. Except as otherwise provided in this probate code, the court shall fix the time and place of hearing of any matter requiring notice and shall prescribe a time for the hearing not less than twenty days after the date the notice is served unless the court finds there is good cause shown to shorten the time period to less than twenty days. The court shall also prescribe the manner of service of the notice of such hearing.

2. In the case of proceedings against unknown persons or persons whose address or whereabouts are unknown, the court shall prescribe that notice may be served by publication within the time and in the manner provided by the rules of civil procedure.

3. No notice shall be served at any time by posting.

4. In lieu of the foregoing, the notice may direct each interested party to file the party’s objections thereto in writing, if any, on or before a date certain, to be set out in the notice and to be not less than twenty days after the day the notice is served upon the party and that unless the party does so file objections in writing that the party will be forever barred from making any objections thereto. Said notice shall be served upon each interested party personally in compliance with the rules of civil procedure, or upon those parties not under legal disability by ordinary United States mail. In the event objections thereto are timely filed, the court shall fix the time and place of the hearing for the judicial determination of the issues raised.

5. When notice in probate proceedings is served upon an interested party by United States mail, the service is made and completed when the notice being served is enclosed in a sealed envelope with the proper postage thereon addressed to the interested party at the party’s last known post office address and is deposited in a mail receptacle provided by the United States postal service.