I have a request from my downstream Exchange admins to look into implementing ARC sealing in some postfix relay servers we use for address rewriting. From the bit of research I've done, it looks like this would require being implemented in an external milter. I had not even heard of ARC before today; it looks like it's an experimental RFC from 2019 that Microsoft and Google have implemented in their systems. Does anyone have experience with ARC or how to set it up with postfix?
Thanks RobertC
