How can I know if my Iphone is jailbroken?
I am using an Iphone 6 -version 10.2.1.
I have been having doubt that my Iphone has been hacked and people who hacked my Iphone might read all the emails in my Iphone. A fews weeks ago I made question here about how I can know if my Iphone is hacked. Since then I changed password for my Icloud, Iphone passcode, emails as I received some advices here but I still can't help being worried because many strange things continue happening to me recently. People who I doub that they hacked my Iphone have no my email adress but many things they said was the same what I had written in my emails lately. People who I doubt that they have hacked me have a lot of experience with computer technology because it's their job. I'm not a friend with those people but I doubt that someone who I had conflict with ask them to hack me. This person has my telephone number.
My question is how I can know if my Iphone is jailbroken? Can people hack my Iphone remotely and secretely?
What should I do more to protect my Iphone from being hacked?
Thank you for advance.
iPhone 6, iOS 10.2.1