Iowa Code § 499A.3B: Notice of members meetings.

Unless the articles of incorporation or the bylaws otherwise provide, written notice stating the place, day, and hour of the meeting and, in the case of a special meeting, the purpose or purposes for which the meeting is called, shall be delivered no less than ten nor more than fifty days before the date of the meeting, either personally or by mail, by or at the direction of the president, the secretary, or the officer or persons calling the meeting, to each member entitled to vote at the meeting. If mailed, notice is deemed to be delivered when deposited in the United States mail addressed to the member at the member’s address as it appears on the records of the cooperative, with postage prepaid.