Faking e-mails: Why it is even possible ?

[sidemoon]

 Phishing and business e-mail compromise attacks rely on fake e-mails. But why is it so easy for attackers to make them so convincing?

Sometimes it’s easy to spot phishing e-mails just by checking the “From” field. However, that’s not always the case; making a fake e-mail indistinguishable from a genuine one actually is possible. If an attacker knows how to do such a thing, the targeted organization is really in trouble. 

Most people wouldn’t have a second thought before clicking on a malicious link or file that they got in an e-mail seemingly from their boss or their top client — and it’s hard to blame them, especially if there’s no way to tell the e-mail was spoofed.

But why is it possible to forge a perfect fake e-mail in the first place? 

Full article here:
https://www.kaspersky.com/blog/36c3-fake-emails/32362/