campaign emails are still not being delivered to employees

Summary:

Hi Team,

I am facing an issue with HCM Communicate campaign email delivery in our DEV environment.

I created and activated the campaign successfully, scheduled the primary email, and ran the following processes:

• Refresh HCM Communicate Audience
• Prepare Campaign Email
• Send Campaign Email
• Track Campaign Email Delivery

All processes completed with Succeeded status.

The audience count appears correctly, and the campaign status is Scheduled/Active.

Additionally:

• "Send Test Email" works successfully.
• I tested both with and without Sender Profile.
• I also verified employee work email addresses and primary email settings.

However, the actual campaign emails are still not being delivered to employees.