Cannot Send Automatic Test Emails to Internal Domain - Error: "Automatic email is scheduling"

Overview

You are trying to send automated test emails to an email address within your organization, but the emails are not sent and the following error is displayed:
Automatic email is scheduling

The tasks are appearing in Automated Tasks on the dashboard, but they are not appearing in the Tasks tab. At the same time, automatic emails addressed to users outside of your organization are sent out properly.

Information

This issue is happening because the sender's domain (i.e., your company domain) is automatically added to the blacklist (while it is not listed in the blacklist itself) and such emails cannot be sent as a result.

As a workaround, try sending test emails to a test account with a different domain (e.g., Gmail, Yahoo, etc.).