Postfix has the feature you require[0]. Does google support anything along these lines?<p><a href="https:&#x2F;&#x2F;serverfault.com&#x2F;questions&#x2F;321109&#x2F;how-to-prevent-remote-hosts-from-delivering-mail-to-postfix-with-spoofed-from-he" rel="nofollow">https:&#x2F;&#x2F;serverfault.com&#x2F;questions&#x2F;321109&#x2F;how-to-prevent-remo...</a>