We are planning to set up DKIM for a mail domain, example.dk.
I can find a lot of good advice on the Internet. But there's one question I can't find an answer to.
We Use Exchange online for most of our mail, but we also have an on-premise SMTP server for routing mails from our webservers. And we are using a cloud service for our news letter service. How can DKIM be set up when there's multiple systems sending mail from our example.dk domain?
All the guides I have found on the Internet are about a setup with only one mail system.
Best regards Holger Nielsen