This is absolutely not difficult to get right. Run OpenDKIM and OpenDMARC on your server along with your email stack (I use Postfix and Dovecot). Use a tool suc

This is absolutely not difficult to get right. Run OpenDKIM and OpenDMARC on your server along with your email stack (I use Postfix and Dovecot). Use a tool such as mail-tester.com to verify compliance.