Reasons for why Batch Email Settings fail
When the sender domain is not verified.
When incorrect API credentials are entered in Arborgold
In Sendgrid's case, the Verification Email has not been verified as Single Sender under SendGrid account.
When SendGrid or Elastic Email Account is inactive for any reason.
After all email credits have been used up for the day (SendGrid Free email plan)
Go to Settings -> Integrations -> Batch Email within Arborgold to adjust the Batch Email settings.
