After Smart Study: How Courts Are Applying the Second Circuit's Landmark Hague Convention Ruling in 2026

On December 18, 2025, the United States Court of Appeals for the Second Circuit issued what has since been considered a leading federal appellate opinion on the availability of email service under the Hague Service Convention. In Smart Study Co., Ltd. v. Shenzhenshixindajixieyouxiangongsi, 164 F.4th 164 (2d Cir. 2025), the court held that the Hague Convention does not permit service by email on defendants located in a country that objects to service via postal channels (in this instance, China), and that no provision of the Federal Rules of Civil Procedure can be invoked to circumvent that prohibition. See id., 172.  The decision resolved a question that had caused division amongst district courts nationwide and has already begun reshaping how litigators approach international service of process. In the months since, courts across the country have been engaging with Smart Study's reach.  This post examines the Smart Study holding and surveys the 2026 decisions that have applied, distinguished, or worked within its framework.

The Smart Study Ruling

The underlying dispute involved a familiar modern scenario: a global intellectual property owner suing e-commerce sellers based in China for alleged counterfeiting. Smart Study, 164 F.4th at 166.  Smart Study Co., Ltd., a South Korean entertainment company and owner of the popular "Baby Shark" franchise, filed suit in the Southern District of New York in July 2021 against 58 China-based companies alleged to have manufactured or sold counterfeit Baby Shark merchandise through various online platforms.  Id. at 168-69.  Seeking swift relief, Smart Study obtained ex parte orders including a temporary restraining order and authorization to serve all defendants by email under Federal Rule of Civil Procedure 4(f)(3).  Id. Smart Study then moved for default judgment against those defendants who failed to appear.

The district court drew a critical distinction based on whether each defendant's physical address was known. For the 49 defendants whose physical addresses could not be determined despite reasonable diligence, the Convention did not apply under its own terms, and email service was valid; the Court entered default judgment against them. But for two defendants for whom Smart Study possessed physical addresses in China, the Hague Convention applied and email was not an acceptable method under its provisions. It was the denial of default judgment as to those two defendants that Smart Study appealed to the Second Circuit.

The Second Circuit affirmed, delivering what can only be considered an unequivocal answer. The Court's determination that email service was not available rested on the following analysis: 

• The Hague Convention provides a “closed universe” of permissible service methods; only those specifically approved should be permitted for foreign service into signatory countries.  See Smart Study, 164 F.4th at 170 (citing Water Splash, 581 U.S. 271, 273 (2017)) (stating that the Convention “specifies certain approved methods of service and pre-empts inconsistent methods of service wherever it applies.”).

• China’s explicit objection to service methods provided by Article 10 of the Hague Convention, a section which includes service via “postal channels” precludes an argument that service via email is permissible under the terms of the Convention. See id.

• The alternative service avenue provided by Federal Rule of Civil Procedure 4(f)(3) is not available to allow email service as it permits service “not prohibited by internation agreement”—email service is prohibited by the Hague Convention, most clearly where the signatory country objects to Article 10 service.  See id. at 172.

• Article 15 of the Hague Convention may allow for an ‘urgency exception’ but default judgment would not qualify as a party seeking “provisional or protective measures.” See id. at 173

The Smart Study Court did provide some avenue towards email service; noting that Article 1 of the Hague Convention states that it does not apply where “the address of the person to be served with the document is not known." See id. at 168.  Thus, here a plaintiff demonstrates, after exercising reasonable diligence, that a defendant's physical address cannot be determined, the Convention does not govern and alternative service methods, including email, remain on the table.

2026 Decisions Applying Smart Study

In the four months since the Second Circuit handed down Smart Study, several courts have looked to apply its reasoning to the case at hand:

Lojek v. Henan Ocean Power Housewares Co., Ltd. (W.D. Wash. 2026)

In Lojek v. Henan Ocean Power Housewares Co., Ltd., Case No. C25-2449-SKV, 2026 U.S. Dist. LEXIS 22429 (W.D. Wash. Feb 3, 2026), the court denied the plaintiffs' request to serve Chinese defendants by email in a patent infringement case, following the Second Circuit's holding in Smart Study. The court found that because the plaintiffs possessed the defendants' physical addresses and could not show that the defendants were attempting to evade service, the Hague Convention governed and email was not an approved method. The desire to avoid the cost and delay of Convention-compliant service was, standing alone, insufficient to justify alternative service under Rule 4(f)(3).

Fox Corporation v. Media Deportes Mexico, S. de R.L. de C.V. (S.D.N.Y. 2026)

In Fox Corporation v. Media Deportes Mexico, S. de R.L. de C.V., 25-cv-6703 (JSR), 2026 U.S. Dist. LEXIS 32173 (S.D.N.Y. Feb. 17, 2026), the court distinguished Smart Study and upheld email service on a Mexican defendant in the context of emergency proceedings, including a TRO and civil contempt sanctions. The court relied on Article 15(3) of the Hague Convention, which permits judges to order "any provisional or protective measures" in cases of urgency, reasoning that a TRO and contempt sanctions—unlike the final default judgment at issue in Smart Study—are textbook examples of provisional relief. The decision establishes a narrow but important exception: email service may still be authorized in a country that has objected to Article 10 when the relief sought is genuinely provisional or protective rather than a final judgment on the merits.

Glob. Brother SRL v. Zhuliang (M.D. Fla. 2026)

In Global Brother SRL v. Zhuliang, Case No. 8:25-cv-00980-KKM-NHA, 2026 U.S. Dist. LEXIS 64835 (Mar. 25, 2026), the court applied Smart Study and granted plaintiff’s request for email service on a Chinese defendant where the physical address provided by the defendant’s was ultimately nonexistent. The court found that the plaintiff made “‘reasonably diligent efforts to learn the defendant’s mailing address’ before concluding that the address of a defendant was unknown.” Here, the plaintiff attempted service to a physical address through China’s governmental authority for international service who informed the plaintiff that the address provided by the defendant “does not exist.” Testimony from plaintiff’s counsel that the plaintiff could not locate an alternative physical address for the defendant was sufficient for the court to find that the address was unknown and that, therefore, the Hague Service Convention does not apply. The court granted plaintiff’s request for email service to a known email address through which the defendant had been sending and receiving communications relating to the same matter.

EE Holding Grp. LLC v. Zhongxin (N.D. Ga. 2026)

In EE Holding Group, LLC v. Zhongxin, No. 1:23-cv-03770-VMC, 2026 U.S. Dist. LEXIS 78287 (N.D. Ga. Feb. 6, 2026), the court applied Smart Study and determined that the Hague service Convention does not apply because the address of the defendant is unknown. The court found that plaintiff did employ reasonably diligent efforts to learn the defendant’s mailing address and was still unable to locate an address making the location of the defendant “unknown” for purposes of the Smart Study analysis. Thus, the Hague Service Convention does not apply. Considering the efforts of the plaintiff to learn the defendant’s mailing address and the circumstances of the case, the court found that the plaintiff’s proposed electronic service method was “reasonably calculated to apprise Defendants of the pendency of this action.” In other words, electronic communication was permissible. 

The Road Ahead

Smart Study has settled the law in the Second Circuit, and the law elsewhere will continue to evolve. The Seventh Circuit has just issued a similar ruling to that of Smart Study in Kangol LLC v. Hangzhou Chuanyue Silk Import & Export Co., Ltd., No. 25-2205, 2026 U.S. App. LEXIS 15376 (7th Cir. May 29, 2026), which also involves email service on Chinese defendants. With the Seventh Circuit following the Second Circuit's lead in narrowing the construction of the Hague Convention—finding its explicitly mentioned avenues for service to be exclusive—the Smart Study ruling, and the point of view it espouses, continues to grow in its persuasive force; if other courts diverge, a circuit split could invite Supreme Court review. 

So what is the practical effect on practitioners? 

First, case timelines in actions against foreign defendants in Hague Convention signatory countries that have objected to Article 10—a group that includes most notably, China, India, and Mexico—must account for the time and expense of service through the receiving country's Central Authority.  Relatedly, the decision carries significant strategic implications for defendants. Foreign defendants in signatory countries may now have stronger incentives to decline waiver of service requests, because the Convention's preemptive power means that declining waiver forces plaintiffs to navigate the full Hague Convention process, creating tactical advantages: extended time to prepare a defense, increased litigation costs for plaintiffs, and the possibility that plaintiffs may be unable to complete service at all. For foreign corporations, consider whether inclusion of a U.S.-based subsidiary as a named defendant can leverage the appearance of the foreign corporate parent. 

Second, where a defendant's address is genuinely unknown after reasonable diligence, email service remains available, but courts will likely scrutinize whether the plaintiff truly could not ascertain a physical address. 

Third, in cases involving truly urgent provisional relief such as TROs, there may be room under Article 15(3) to authorize email service for the limited purpose of notifying defendants of emergency proceedings—though this exception will almost certainly not extend to final judgments or permanent injunctions.