Iowa Code § 681.8: Notice of assignment — notice to creditors.

The assignee shall forthwith give notice of such assignment by publication in some newspaper in the county, which shall be continued, once each week, at least six weeks, and forthwith send a notice by mail to each creditor of whom the assignee shall be informed, directed to the creditor’s usual place of residence, requiring such creditor to file in the office of the clerk of the district court within three months thereafter the creditor’s claims under oath.