Mailrelay supports full DMARC compliance.
For DKIM setup, visit: https://blog.mailrelay.com/en/2019/03/22/mailrelay-v3-configuring-spf-custom-domain-and-dkim
Add 'include:spf.ipzmarketing.com' to your SPF record. For more information, visit: https://blog.mailrelay.com/en/2019/03/22/mailrelay-v3-configuring-spf-custom-domain-and-dkim