Can my husband use my hacked e-mail in family court as evidence?

I and my husband are going through divorce and child custody battle. My husband is asking for custody of current son (2yrs old) as well as our unborn child. If everything plays fair, I don’t see any way I could lose child custody over my husband as I was the primary care taker of our son and my husband was absently both financially and physically. However, I am quite certain he has hacked into my e-mail (that it used to be stored in my iphone but not anymore, as my husband convinced me to delete that account from my phone) and has information that may put me into very difficult position. I am wondering if he can use these evidence in family court legally. If so, is there any way I can try to stop this happening?