We have published two articles on our website that explains what DKIM and DMARC are and why it is good to add them to your domain name (if you have not done it yet). It is especially important if you send email newsletters. Click on the links below to read the articles:
> Article: DKIM – How to add this to your domain
> Article: DMARC – How to add this DNS record to your domain
See also
> How to add / update SPF for a domain