Texts and emails relevant to your case can and should be exhibits. Often times, they prove or disprove that certain conversations were had. In the family law context, they often show certain things like discussion of finances, custody, verbal abuse, or even the overall character of a spouse. But there are barriers to cross before the texts can be admitted as evidence.
First, the text message must be authenticated. That means that the text message, if being offered to prove the matter that it is being introduced for, must be what the proponent claims. To put this in easier language, “it is what you say it is.” If you wanted to prove that on September 3, 2020, your ex was out of town, and you have a chain of texts where you ex says to you “I’m just hanging out at the hotel in Dallas,” then you first must prove to the court that 1) you received this text on September 3, 2020 and 2) that the person who texted that to you was in fact your ex. The latter is most often proved by testimony that it is your ex’s phone number and that it is the phone number he has always used to text you with, and that you only ever text with him on that number (i.e., no one else routinely uses that phone number to text you). After authentication there are other barriers to overcome.
The other barriers are objections based upon the rules of evidence. There are many objections to this end. But one that is apparent at the beginning is that text messages are technically hearsay. A hearsay statement is one made by a declarant outside of court, offered to prove the truth of matter asserted. A text message is an out-of-court statement and is being offered to prove the truth of what was said. In the example above, it is a text (statement) made by your ex (a declarant) and it is being offered to prove that your ex was in fact out of town on September 3, 2020 (truth of the matter asserted, and obviously not made at court). Thankfully, as far as hearsay goes, your ex’s text is an exception if properly authenticated. A party’s own statement is a hearsay exception.
Needless to say, the rules of evidence are fairly complicated. But in all cases, your attorney needs to review all the evidence that you have. This includes texts and emails from your spouse or third parties that are relevant to your case.