How to Test Email Deliverability

Prerequisites

Before testing deliverability, make sure you have:

• A configured email server (Postfix)
• SPF, DKIM, DMARC set up (Articles 91-93)

Method 1: Send Test Email to Gmail

Connect to your VPS:

ssh hxroot@YOUR_SERVER_IP -p 22

echo "Test email body" | mail -s "Deliverability Test" your-gmail@gmail.com

Check Gmail inbox (and spam folder).

Method 2: View Email Headers in Gmail

1. Open the test email in Gmail
2. Click three dots → "Show original"
3. Look for:
• Authentication-Results: spf=pass
• Authentication-Results: dkim=pass
• Authentication-Results: dmarc=pass

Method 3: Use Online Email Testing Tools

• Mail Tester – https://www.mail-tester.com
• GlockApps – https://glockapps.com
• MXToolbox – https://mxtoolbox.com/deliverability

To use Mail-Tester: send an email to the address provided, then view score.

Method 4: Check Blacklists

Check if your IP is blacklisted:

dig +short your.ip.here.zen.spamhaus.org

Or use online tool: https://mxtoolbox.com/blacklists.aspx

Method 5: Send Automated Test Sequence

Create a script to send to multiple test inboxes and track results.