What Email Deliverability Is and Why It Matters

Why this matters

Deliverability determines whether your message reaches the inbox or gets silently discarded before anyone sees it. Understanding this gap between 'sent' and 'delivered' is the foundation of every effective email program.

Try it yourself

1. Send a test email to a Gmail account and check the 'Original' headers — locate the 'X-Spam-Status' or 'Authentication-Results' line and note what it says.
2. Look up your domain on MXToolbox (mxtoolbox.com/blacklists) and record whether it appears on any blacklists.
3. Compare the 'Sent' count vs. 'Delivered' count in your last campaign's report and calculate the delivery rate percentage.

References

• Mailgun Deliverability Guide