While I was looking for a clue why I the mails to my Hotmail address were blocked, I found something dealing with CAN-SPAM Act. I think it did not appear previously here, please let me know if this is the case !
In some words : to comply with this Act, the headers have to contain something like:
List-Unsubscribe: <mailto: firstname.lastname@example.org?subject=unsubscribe>, <http://www.example.com/unsubscribe.html>
I’ve understood that this was just for mailing-lists, but I suspect that Microsoft checks the existence of this header for all mails arriving to their servers.
Is there a way to include such an option in Mail-in-a-Box, without breaking all the fantastic work already done ? I think it is “just” a configuration in Postfix (refer to : List Unsubscribe Header: Why and How to Use | Mailtrap Blog) but I did not succeed in making it work on my MiaB server.
Have a good Sunday !