How do companies such as Gmail detect email spoofing

Question

If you send a spoof email to a Gmail account, Gmail detects this somehow, and puts this email in your "spam" folder.

How does this work?

Using Google's secret spam detection filters, which are presumably based on known email validation techniques. — Alexander O'Mara, Jan 18 '16 at 19:22
I'm voting to close this question as off-topic because it's not a programming question. — Toby Speight, Jan 18 '16 at 19:57

score 3 · Answer 1 · answered Jan 18 '16 at 19:22

3

Google checks SPF and DKIM to find out what servers (and signatures) are required for mail sent from a domain name.

answered Jan 18 '16 at 19:22

SLaks

1 Answers1