Actually, you do. It's risky, but you absolutely can ignore the suit. If you turn out to be wrong about proper service, then you get stuck with the outcome. So it may not be wise. But you absolutely can do nothing, and then attack any efforts at collection by arguing that the prior judgment is void. Personal jurisdiction is a constitutional requirement. Without adequate service of process, the court does not have the power to adjudicate the matter. Any judgment entered without service of process is void.
The Due Process Clause of the Fourteenth Amendment limits the power of a state court to render a valid personal judgment against a nonresident defendant.
Kulko v. California Superior Court, 436 U.S. 84, 91, 98 S.Ct. 1690, 1696, 56 L.Ed.2d 132 (1978). A judgment rendered in violation of due process is void in the rendering State and is not entitled to full faith and credit elsewhere.
Pennoyer v. Neff, 95 U.S. 714, 732–733, 24 L.Ed. 565 (1878). Due process requires that the defendant be given adequate notice of the suit,
Mullane v. Central Hanover Trust Co., 339 U.S. 306, 313–314, 70 S.Ct. 652, 657, 94 L.Ed. 865 (1950), and be subject to the personal jurisdiction of the court,
International Shoe Co. v. Washington, 326 U.S. 310, 66 S.Ct. 154, 90 L.Ed. 95 (1945).
World-Wide Volkswagen Corp. v. Woodson, 444 U.S. 286, 291, 100 S. Ct. 559, 564, 62 L. Ed. 2d 490 (1980)
It is a bold move, but an option available to a nonresident to ignore a pending proceeding and take the risk that a subsequent challenge to personal jurisdiction will prevail. Insurance Corp. of Ireland, Ltd. v. Compagnie des Bauxites de Guinee, 456 U.S. 694, 706, 102 S.Ct. 2099, 72 L.Ed.2d 492 (1982) (“A defendant is always free to ignore the judicial proceedings, risk a default judgment, and then challenge that judgment on jurisdictional grounds in a collateral proceeding.”).
Stidham v. Whelchel, 698 N.E.2d 1152, 1156 (Ind. 1998)