From United States v. Vaghari, 2009 U.S. Dist. LEXIS 64793 (E.D. Pa. July 27, 2009):

Defendants argue that the emails that form the basis of Overt Acts 1-4, 10-11, 15, 17, 26, 30, and 35-36 cannot be properly authenticated and therefore may not be introduced into evidence. *** According to defendants, as "the government has no witness who can testify that the e-mails are what the government purports them to be," the emails cannot be authenticated under Federal Rule of Evidence 901. ***

"The requirement of authentication or identification as a condition precedent to admissibility is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims." Fed. R. Evid. 901(a). The Third Circuit has "repeatedly noted that the burden of proof for authentication is slight." Lexington Ins. Co. v. W. Pa. Hosp., 423 F.3d 318, 328 (3d Cir. 2005) (internal quotation marks & citation omitted). "[C]ircumstantial evidence may, in principle, suffice to authenticate a document. . . . All that is required is a foundation from which the fact-finder could legitimately infer that the evidence is what the proponent claims it to be." Link v. Mercedes-Benz of N. Am., Inc., 788 F.2d 918, 927 (3d Cir. 1986) (internal quotation marks & citations omitted). The Third Circuit has articulated the standard for the authentication of documents as follows:

[T]he showing of authenticity is not on a par with more technical evidentiary rules, such as hearsay exceptions, governing admissibility. Rather, there need be only a prima facie showing, to the court, of authenticity, not a full argument on admissibility. Once a prima facie case is made, the evidence goes to the jury and it is the jury who will ultimately determine the authenticity of the evidence, not the court. The only requirement is that there has been substantial evidence from which they could infer that the document was authentic.

Lexington Ins. Co., 423 F.3d at 329 (emphasis in original) (internal quotation marks & citations omitted).

Federal Rule of Evidence 901(b) provides a non-exclusive list of "examples of authentication or identification conforming with the requirements of this rule." Defendants rely on Rule 901(b)(1) — "[t]estimony that a matter is what it is claimed to be." This, however, is not the sole method of authentication. Rule 901(b)(4) provides for authentication through "[d]istinctive characteristics and the like. Appearance, contents, substance, internal patterns, or other distinctive characteristics, taken in conjunction with circumstances." Other courts have authenticated emails in this manner, relying on the email addresses in the headers, explanations in the body of the emails, defendants' conduct after receiving the emails, and other circumstantial evidence. See, e.g., United States v. Siddiqui, 235 F.3d 1318, 1322-23 (11th Cir. 2000); United States v. Safavian, 435 F. Supp. 2d 36, 39-42 (D.D.C. 2006).

The government provided three emails as attachments to its response. The emails contain Vaghari's name and email address in the headers. Moreover, the government contends that the emails were obtained in hard copy form from Vaghari's apartment, bolstering their authenticity. These distinctive characteristics suffice to withstand defendants' authenticity challenge at this stage of the proceedings. Accordingly, the Court denies defendants' Motion to Strike on the ground that the emails cannot be properly authenticated.