I have a bunch of domains, let's say:
My mail server is running on
mail.example.net. I only use the domain
example.com to send and receive emails. All the other domains are only used to receive emails which are any way redirected to the
example.com has SPF, DKIM and DMARC working properly.
In order to know if I'm being impersonated from the other domains (an info given by the
ruf DMARC report), I was wondering if I needed to configure DKIM besides DMARC and on the .be, .org and .net as well?
If I'm not wrong and from my understanding, I think I only should configure DKIM and DMARC on the domains used only for redirection. I don't think SPF is mandatory on the domains not used to send emails.
Please give me your recommendations.