I did a howto about all smtp policies you must have with your email server if you want that your emails have a chance to be delivered to the other email platforms (such as gmail, orange, Microsoft…) and not rejected or tagged as spam.
I talk about reverse dns (rdns), sender policy framework (spf), DomainKeys Identified Mail (DKIM) and Domain-based Message Authentication, Reporting & Conformance (DMARC).
Of course all of this is not needed if you have configured a smarthost to send your email, but I have had the case that my email was rejected by a SURBL blacklist because the smtp of my provider was considered as a spam sender…and you can do nothing except changing your smarthost. Hence the interest to send yourself your email.
The howto is pending you reading at https://wiki.nethserver.org/doku.php?id=email_protection_resources, I hope that at the end it becomes official documentation.
You will understand quickly that there will be a new feature soon in the email server
I will call some people already interested by this feature, but you can add your grain of salt if you know something.