A cloud engineer deployed an email server in a public cloud. Users can access the email server, but the emails they send cannot reach their destinations. Which of the following should the cloud engine

Confirming the email server configuration addresses the most common root causes of outbound delivery failure, including misconfigured SMTP relay settings, incorrect MX or PTR DNS records, or corrupt software. Since users can already connect to the server, the problem is isolated to how the server processes and forwards outbound mail, making configuration verification and software integrity the logical first step.

Validating the security certificate addresses TLS/SSL handshake failures but would typically cause recipient-side connection errors rather than preventing all outbound email delivery.

Confirming email encryption service is a secondary concern because encryption misconfiguration generally produces bounce-back or error messages rather than causing silent outbound delivery failure.

Consulting the cloud vendor anti-spam policy is relevant if port 25 is blocked, but this is an escalation step that should follow verifying the server's own configuration first.