Years ago as a Reserve Deputy Sheriff I was given an e-mail account for the Sheriffs Department it was suggested to me that I use only that account for contact purposes with other members of the Sheriff's Department. The worry was not so much about hacking but about legal issues. If a situation were to occur in which I be came a defendant in a lawsuit, my Department e-mail account would be open for discovery and if my "private" e-mail account showed up in that department account, then it to would be fair game for review.
All of a sudden ALL my private business, my private life would be "public"!
I got the same advice when I was elected to public office.
In those days we did not have all the electronic devices we have now. An iPhone can contain several email accounts and I can see how easy it could be (just look at Hillary) for one to just MIX these in the course of the day.
All should be warned by what is going on in Washington to keep personal business separate from public business on your electronic devices.
By the way has anyone noticed that is you research an item you are interested in purchasing via the web, that all of a sudden the POP UP Ads on your computer contain ads for the item you just looked at. WOW! Have we all been hacked?