Hackers use such tactics as they are incredibly effective.
If it sent from an address you are not in regular contact with it is advised not to open the email.
To create an exhaustive list of all the types of malicious email could fill a novel and hackers don’t just use the same method over and over again.
One of the ways to stay ahead of the curve looks for certain traits in emails known to be used, such as often they are written in poor English.
Despite the number of attack vectors, available email is easily used by both the experienced and inexperienced hacker.
This is a massive majority considering the sheer amount of attack vectors available to hackers.