How is it normal for sendmail to send emails from any domain?

Question

I just tried my hands using sendmailas described inMail::Sendmail

I saw that I was able to send mail with a user ID from any domain, as long as I have an SMTP server running on localhost. How is everything okay? or am I missing something?

For example, I was able to deliver emails from an address such as <myname>@microsoft.com, and it did the same in my gmail inbox. He didn’t even get into the junk folder /

Answer 1

Congratulations: you just discovered email spoofing ! :)

SMTP , , , . , - , - , , sendmail, .

(, microsoft.com), , , . , , ; , Framework .

, microsoft.com, , , . , , , , .