Can I sue for Deformation of Character.....

It sounds as though the recipients of the e-mail, as well as the police, recognize that the content of those e-mails was manufactured. If that is true, then the first question is whether it would be worthwhile for your husband to sue. Lawsuits cost money. Besides, depending upon the sort of defamatory statement involved, there may be a need to prove damages. (As a New York attorney, I cannot advise you as to the application of Colorado state law). I think the best thing for you to do is to have an attorney write a letter to the person who wrote the offensive e-mails, demanding that he or she cease and desist from any such activities in the future. It may cost you a few hundred dollars, but a defamation lawsuit would cost many thousands, and a letter from an attorney will probably dissuade the e-mail writer from repeating the same transgressions. Good luck to you.