I have looked at the docs and forum, but don’t see a way to enable DKIM signing for the host domain such as myserver.domain.com. Is it possible to enable DKIM signing for the host domain? This would help ensure e-mails are delivered appropriately when coming from the ApisCP host. I have SPF and DMARC setup for the host and it does help but DKIM signing I believe is the key to resolving this.
Ideally, you want to avoid mail originating from the server domain as anyone can ditch the sending hostname and thus fallthrough to the server hostname - this becomes a spam problem.
What’s your use case?