My ex and I are going through a custody battle. I have had my email hacked and broken into many times and I receive forwarded emails of my ex talking to someone about these happenings. Recently I found out in one of the emails that she is accessing my iPhone and blocking and unblocking her phone number in my contacts, then sending messages remotely from my iPhone to herself while she is blocked so I will not see the responses. WHAT CAN I DO??? I have changed my passwords, iCloud accounts, everything I can think of to prevent this but it continues. Is this even possible? If so how is it done? I want her to get in trouble in court as she is trying to keep my 9month old son away from me. Please help.
Inform your lawyer immediately. If you don't have a lawyer, get one now. It is essential that what is happening is documented. Law enforcement (your local police, constabulary or gendarmerie) may be able to assist if you are being harassed.
If you can afford to purchase a new iPhone, even a refurbished 5s without all the extra RAM & whatnot, do so. Create new email & iCloud accounts. Use a password manager such as LastPass, any two-factor authentication available and turn off the old phone.
To block your Caller ID information from being displayed temporarily for a specific call: Dial *67. You will need to dial this for each call you want to block. Enter the number you wish to call (including area code). Tap the Call button. The words "Private," "Anonymous," or some other indicators will appear on the recipient's phone instead of your mobile number.
If you have SMS forwarding turned on, that could be part of it. From https://support.apple.com/kb/PH22363?viewlocale=en_US&locale=en_US
On your iPhone, tap Settings > Messages. Tap Text Message Forwarding.
Also, I would turn on two-factor authentication for your Apple ID that you use for messaging at http://appleid.apple.com
See https://support.apple.com/en-us/HT205075 for some more information on that one.