Email Diagnostics: Live Queue Spikes, Delivery Tests & Blacklist Check (Tab 7: Diagnostics)

Email Management • Tab 7: Diagnostics • Native 1920x1080 View

📌 Purpose & Quick Summary

Use the Diagnostics tab to troubleshoot why emails are failing to send or receive. You can verify that your domain's DNS records (MX, SPF, DKIM, DMARC) are correct, view real-time Postfix system logs, and inspect or flush the outbound mail queue.

🖥️ Interface Tour & Elements

1. Target Node Selector: Select which website domain to diagnose.
2. DNS Health Check Table: Probes public DNS resolvers to verify that MX, SPF, DKIM, and DMARC records match BoostonCP best practice values.
3. Live Mail Logs Viewer: Displays the last 50 lines of /var/log/mail.log with color-coded success and error lines.
4. Mail Queue Manager: Displays the count of pending messages in the Postfix mail queue and provides Flush Queue and Purge buttons.

🛠️ Step-by-Step Instructions: Diagnosing Delivery Issues

1. Verifying DNS Records

1. Select your domain in the Choose a Website dropdown.
2. Under DNS Health Check, click Check Records.
3. Inspect the results table:
   • MX Record: Checks if mail.yourdomain.com is registered with priority 10.
   • SPF Record: Checks if v=spf1 ip4:YOUR_IP ~all is detected.
   • DKIM Record: Checks if the default._domainkey public key matches the private key on the server.
   • DMARC Record: Checks if v=DMARC1; p=none is present.
4. Any missing record will display a red status badge with instructions on what value to copy to your DNS manager.

2. Viewing Real-Time Mail Logs

1. Under Live Mail Logs, click View Logs.
2. Review incoming and outgoing connections. Look for lines containing status=sent (Success) or status=bounced / deferred (Failure) to see the exact rejection reason returned by remote servers.

3. Managing the Outbound Queue

1. Under Mail Queue, check if messages are stalled.
2. If emails are queued due to temporary network issues, click Flush Queue (postqueue -f) to force Postfix to attempt immediate redelivery.