You want to add or delete an enabled sender in the EFP portal.
Email Fraud Protection
Enabled senders are third-party senders that you allow to send email on your behalf. You can enable senders for each registered domain and their subdomains individually.
1. On the Configuration page, in the Enabled Senders area for the registered domain, click Enable a Sender (“+” icon).
2. Select the sender to enable from the Email service provider drop-down menu.
3. Click Enable. The sender is added to the Enabled Senders list. The sender will be configured as needed for SPF authentication. If the sender supports DKIM authentication, a warning message in the DKIM Keys area appears, prompting you to configure a DKIM key. To disable a sender, click Disable this sender? (" X " icon).