Iowa Code
Chapter 461B - USE OF STATE WATERS BY NONRESIDENTS
Section 461B.6 - Optional notification.

461B.6 Optional notification.
In lieu of mailing said notification to the defendant in a foreign state, plaintiff may cause said notification to be personally served in the foreign state on the defendant by any adult person not a party to the suit, by delivering said notification to the defendant or by offering to make such delivery in case defendant refuses to accept delivery.
[C62, 66, 71, 73, 75, 77, 79, 81, §106A.6]
C93, §461B.6