Rick Wash, associate professor of computer science and cybersecurity at Michigan State University, listed the hallmarks of email scammers. Many can independently determine whether the letter in front of them is fake or real. Most intuitively feel that something is wrong with the content of the message, the expert says.
So what details hint that the email was sent by attackers? By themselves, such letters offer people to transfer money somewhere, launch a particular program, enter a password, follow a link, etc. Similar messages are called phishing.