DMARC compliance through both SPF and DKIM.
See https://www.copernica.com/en/articles/signing-your-emails-with-dkim
You could add 'include:_senderspf.copernica.com' to your SPF record. Contact Copernica to verify this or visit: https://www.copernica.com/en/documentation/spf
Copernica is a member of the Certified Senders Alliance. Click the CSA Logo on the right to find the certificate on CSA's website.