Originally posted by: jonks
Short answer is, of course, it depends. Yes you can try to use them, but the judge might not admit them if he feels you haven't provided sufficient authentication, and how prejudicial to the other side the content of the email is.
Kearley v. State, 843 So. 2d 66, 2002 Miss. App. LEXIS 560 (Miss. Ct. App. Oct. 22, 2002).
After being convicted of sexual battery, defendant appealed on issues regarding the proper authentication of email messages he had allegedly sent to victim. During the trial, the victim had testified that she had received and printed the email messages on her computer and the appellate court held that this testimony was sufficient authentication under the rules of evidence, upholding defendant's conviction.
What's the difference between you bringing in a printed email for which you lost the original electronic version vs bringing in a letter you say the other side wrote and mailed to you? You could have faked the letter too for all the judge knows. You will have to provide some level of authentication however, and you can do this short of pulling ISP date/timestamp records.
If you introduce it as evidence and the other party claims they never sent the letter, then they are lying and it's really rare for a party to tell an outright lie that can be discovered through electronic back-tracking. They may say something like "I don't remember sending that" but as far as it being admissible as evidence, sure it is, just like the letter you claim they wrote is. If you submit an affidavit or testify that you printed out the email but lost or deleted the original, that would likely be sufficient, especially if the opposing counsel doesn't object. The trier of fact can simply weigh how much he thinks that particular piece of evidence is worth. Evidence (such as trial testimony) is weighed by the trier of fact. Admissibility is a legal question for the judge, but once he lets it in, the jury figures out how much credibility they assign to it, just like they do with any oral testimony given. They don't have to accept everything presented as true. A juror could think "ok, the judge admitted that email, but you know what? I think the guy faked it and I believe the other party when he said he didn't send it. I found him more credible and believable."
Course the emails can also be thrown out as hearsay depending on what you want to use them for. In any event, it doesn't hurt to try to introduce them.