In a recent federal court case (Benton v. Dlorah, Inc., 2007 U.S. Dist. D. Kan, Oct. 30, 2007), the plaintiff testified at her deposition that she had deleted emails related to the case. The court ruled that deleting emails did not necessarily remove them from the plaintiff’s possession. It reasoned that deleted emails should be retrievable from her computer system and thus remain within in her control.
With options like Gmail there’s really no reason to delete emails anyway. But particularly if you have a personal injury claim, be careful to keep all emails that may be relevant to the case. If the Court finds that you’ve destroyed evidence, it may instruct the jury to draw an adverse inference from your actions.