Allow addition of DKIM & SPF records for sending e-mails from own domain.

Many platforms allow you to add certain DNS records (DKIM, SPF) to your domain to allow the service to send e-mails on your behalf.

I'm aware PandaDoc offers their "whitelabel" package - but I don't want to send e-mails from a subdomain, I want to send e-mails from my top-level domain - billing@mydomain.com (for example).

Can we please implement this?