In order to configure MailGun with SPF and DKIM you will have to add your domain/s or subdomain/s in their Control panel. Next you will have to add two TXT records in your DNS provided to you by mailgun. 

Once the records have propagated across the internet, MailGun will detect and verify your domain/s.

The SPF record that you will have to add to your DNS (if you already have an SPF record) is:

include:mailgun.org

The DKIM record that you will have to add to your DNS will be shown to you in the “Domain Verification & DNS” section in the MailGun control panel.

Create a free OnDMARC account to test your configuration. 

For more information on how to configure DKIM with MailGun, please click on the button below.