The type of Sender Identity you use to send email can impact your deliverability
and what your recipients see in their inbox.Sendgrid provide the option of
Domain Authentication and Single Sender Verification.Follow the Sendgrid documentation to setup the Sender Identity for your domain.
Configure atleast one verified sender as Castled displays only the verified senders returned by the sengrid API.
For enabling Castled to recieve the email event callbacks webhook needs to be
configured. The URL mentioned below needs to be configured so that the events
callbacks can be listened and processed by Castled.