Hi 7×7,
Hacking email can be a couple of different scenarios.
Try https://haveibeenpwned.com/ to see if you have had your email address compromised.
There is a pretty good chance it is considering how many breaches there have been. (Yahoo, etc)
Set up your social account with two factor authentication to stop your account from being hijacked..
Gmail: https://support.google.com/accounts/ans … 24808&rd=1
Facebook: https://www.facebook.com/help/148233965247823
This will cause the main server to contact you if your account is accessed from an unknown device. So before you can log onto Gmail or Facebook etc, you will be prompted to enter a security code that they have texted to you.
Also, Google has an account history that will show IP and location of attempted logons. That should help cut way down on the hacking.

If an insider hacks your email, it might be harder to detect. Let’s say a drunk girlfriend logs on to your email while you are asleep and sends nasty-grams to your ex. The only way you would know is if there was a message in the Sent folder or Trash.
If a spambot were to infect your email, you might see messages in your sent folder, but by then, as with the girlfriend example, you are already screwed.
Go with the 2 factor authentication and it should help a lot.

Hope this helps!