I am not licensed to practice in Arkansas so the following should not be taken as legal advice, but simply as information intended to be helpful. If you need legal advice, please consult a lawyer who holds Arkansas licensure.
If you testify, you can testify that you received these e-mails. Your ex-wife may deny sending them. The court is then going to have to figure out whether or not it's proper to consider the e-mails or not. Other considerations affect their admissibility; in particular, what they are being introduced to prove. It is impossible to say one way or the other whether the Court is going to admit them or not until they are proposed to be admitted to evidence to prove something in particular, the other side makes its objections, and the court decides how to rule.
Emails are hearsay evidence and there needs to be authentication before they will ever get into evidence. If the e-mail account from where the emails came was accessible to others, it is highly doubtful it would be allowed to be entered as evidence against your ex-wife. The judge decides what form of evidence can be submitted in court and the same is true with emails.
If an e-mail can be connected to the person without there being any doubt of someone else having sent it, then it is possible it could be used as evidence. What level of connection can be established as to your ex-wife may need to be established by a forensic investigation.
Email admissibility in court can vary from state to state. And admissibilty rulings vary from courtroom to courtroom within the same county in a state, sometimes. Federal courts have differing standards, too. And, even if admissible, email evidence is sometimes easy to refute because of the ease with which an email can be sent and made to look like it is the real thing.
Hope that helps.
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