In this digital era, it is increasingly common to introduce correspondence preserved for trial which was initially transmitted by electronic means. People prefer to communicate via email these days as opposed to transmitting letters by regular mail. Thus, this poses the question as to how such electronic messages can be authenticated. Generally speaking, we can assume that if a sender’s email address is located in the “from” line of email correspondence we can assume that the email comes from whomever owns that particular email address. That being said, if another individual obtains the username and password of the alleged user’s email account or if an individual hacks another person’s email account then it is possible for a message to be sent by an individual purporting to be the owner of the email address. Given these possibilities, a trial judge might insist on the proponent laying a substantial foundation before an email can be accepted as evidence.
These electronic messages can often be authenticated by using the same methodology which you would use to authenticate a letter issued by regular mail. One of the ways in which we can authenticate a written document is by identifying the contents of the writing and demonstrating that the information within the message is information known only by the purported drafter. Consistent with this approach, you may be able to show that the content in the message at issue, sent by the purported drafter, is a response to communication which was initially sent to the purported drafter. We call this the reply letter doctrine. The final way you can authenticate, which can be used for messages sent by both regular mail or electronic mail, is to demonstrate that the purported sender of the correspondence took some action which was consistent with the content of the message in dispute.
With regard to email correspondence, a chain of custody can be laid in much the same way as would be done with tangible document transmittal. Basically what we do here is obtain the business records of all of the systems which transmitted the electronic messages so as to trace the message from the end recipient user to the origin of the electronic document. Remember that we don’t need to prove that the message was in fact opened and verified at each location in which the message was handled. We simply need to print out the entire routing record for the document and then establish that the alleged sender of this document had exclusive control or access to the computer which the routing statement indicates the message originated from.
There are times when messages are verified by the use of cryptography or digital signatures. These devices are typically used in large scale financial transactions where recipients of large sums of money or assets need to be verified. Though these two mechanisms provide for increased guarantees of trustworthiness they are not well understood by lay individuals. This means that the proponent of evidence likely needs to bring in an expert who can explain how the technology works to the judge or jurors. After the technology is explained to the trier of fact by this expert then the individual recipient or certification authority of this message walks the jurors through the process of how the message in dispute was transmitted. Essentially demonstrating to the jurors the method by which this particular message processed through the information system. You essentially show the chain of custody for this electronic message from initial distribution to end user. Thus, you have a two step process for laying foundation for these more complex mediums of exchange.
If need be, you can always have an employee of the mail server testify for purposes of authentication. You would bring in whatever employee is in charge of records for the server company. The employee can then give you chain of custody testimony regarding the message’s transmittal through the various servers. The employee witness can also explain why the system is foolproof and demonstrate that there is good reason to believe that the message comes from the individual you claim it comes from. This individual can tell you how she knows where the message initially came from and how she knows exactly where the message ended up. She is thus authenticating that the email did in fact come from a specific person and that the message was not manipulated or modified as it processed through the chain of custody to the end user. Keep in mind what you are doing here. You are simply demonstrating to the court that the trier of fact can rely on you when you say that something is what you say it is. If you say that you have an email sent by Sally on the 24th of May then you need to demonstrate to the court that this truly is an email that Sally sent on the 24th of May. You don’t need conclusive proof of this fact but you need sufficient evidence that the fact is as you claim it to be.
In trial you will often times want to introduce business records. You do not need to bring in a custodian of records for this purpose. You simply need to provide the court with a certification from the custodian of records of that business. Be sure to provide a copy of this certificate to opposing counsel prior to trial so they have plenty of time to inspect it for authenticity. The declaration, attached to the record you plan to introduce, simply needs to say that the document was made at or near the time of the occurrence, that the document was kept in the ordinary course of business, and that it was the regular practice of the business to make that type of document.
By the same token you may want to introduce official government documents. These records are self-authenticating. Thus you don’t need to have a public official come to court to authenticate these documents. You simply need a copy of the official record along with an attesting certificate from the custodian of records. This certificate is usually signed and bearing a seal from the official’s office. However, if you are dealing with a foreign document the foreign official’s attesting certificate may be insufficient. In this instance you may need multiple certificates. One certificate executed by an American official indicating that the certificate of the foreign official is authentic and then of course the foreign certificate.
The rules outlined above are those which pertain to the Federal Rules of Evidence. Most state courts have similar evidentiary rules. That being said, you should always check your state evidentiary rules if you are in state court as they may differ from the Federal Rules of Evidence. For more information on this topic I refer you to Edward Imwinkelried, (2012) Evidentiary Foundations which is an excellent book on this subject matter and the source of the majority of my own information, as outlined above, on this topic.