The following DNS text records are required to be configured for each domain you are relaying mail from to the Sendmetric service. Replace 'yourdomain.com' with your actual domain.
v=spf1 include:sendmetric.com ~all
If you already have an SPF record configured for your domain you only need to add include:sendmetric.com within the SPF record, before the ~all.
DNS records are modified with your DNS provider.