How to check the header email and mark as spam

[vjdj]

Hi
When I send email from my first server to second server in the following way:

Code: Select all

echo "message" | mail -s "Subject" -aFrom:sender_adress\<sender_adress\> recipient_adress

How to mark this email, when someone wants to impersonate a different address as spam?
Now, after instalation vestacp this email falls to received email.
How to protect this problem in vestacp, validate/check field "from"?
I'm using vestacp with Debian 8