Email sender authentication ensures that the ISPs handling messages sent by Custobar know that Custobar has your permission to send emails on your behalf. The authentication is done through a process of whitelabeling.
To get started with the automated whitelabeling, click on settings and go to Email sender authentication under the Advanced tab.
Set up a whitelabel by clicking "Add a whitelable" below and add DNS records to your hosting service.
Make sure to put the right domain, ie. example.com whitelabeling will not help if you send mails for example.net
Save the changes and the whitelabels will be updated. Next, click on the pencil icon to finish the process.
You will find the CNAME records to add to your DNS configuration. Once they are added, click validate to automatically verify the records and finalize the process.
These DNS records associate your sending domain with Custobar: When an inbox provider processes your email, they will see your domain instead of sengrid.net, the email sub-processor used by Custobar.