To allow FeedBlitz to send emails on your behalf, you will have to add them to your SPF record. The SPF mechanism used by FeedBlitz is shown below.
For more information please click the button below.
FeedBlitz support DKIM, and allow you to generate the records from your account.
For further information on configuring DKIM please contact FeedBlitz support.
Create a free OnDMARC account to test your configuration.