Maropost supports DMARC compliance via DKIM and SPF. See https://galaxy.maropost.com/s/article/Set-Up-and-Manage-Sending-Domains
For DKIM setup, see: https://galaxy.maropost.com/s/article/Set-Up-and-Manage-Sending-Domains
For SPF setup, see: https://galaxy.maropost.com/s/article/Set-Up-and-Manage-Sending-Domains