To allow OfficeRnD to send emails on your behalf, you will have to add them to your SPF record. The SPF mechanism used by OfficeRnD is shown below.
OfficeRnd support DKIM and you will have to create a TXT record in your DNS with the value that they provide you.
For further configuration instructions please click on the button below.
Create a free OnDMARC account to test your configuration.