Definition
Email deliverability rate is the percentage of emails you send that are successfully delivered to the recipient's inbox, as opposed to bouncing or being routed to the spam folder. High deliverability means your mail is reaching the reader as intended.
Deliverability is more than raw acceptance. An email can be accepted yet land in spam, where it is effectively lost. So the rate is best understood as the share of mail that both reaches the server and lands where it will be seen and read, protected by good reputation and engagement.
Deliverability vs Conversion Rate
| Metric | What It Measures |
|---|---|
| Deliverability rate | Mail reaching the inbox |
| Open and click rates | Mail being engaged |
| Conversion rate | Mail driving an action |
Deliverability is a upstream condition for the rest.
What Drives Deliverability
| Factor | Influence |
|---|---|
| Sender reputation | Trust providers assign to you |
| Authentication | SPF, DKIM and DMARC confirmation |
| Engagement | Recipient opens and clicks |
| List quality | Clean, opted-in addresses |
| Complaint rate | Spam reports against you |
These decide where your mail lands.
How to Improve Deliverability
- Keep the list clean: Remove bounces and inactive addresses.
- Authenticate properly: Set up SPF, DKIM and DMARC.
- Respect engagement: Prune non-openers and keep content relevant.
- Monitor complaints: Keep spam reports low.
Related Glossary Terms
Abandoned Cart Email
An abandoned cart email is an automated message sent to customers who added items to their online shopping cart but left without completing the purchase. It is one of the highest-converting email types in ecommerce.
Abuse Complaint
An abuse complaint is a report from a recipient who marks an email as spam, which negatively affects sender reputation and deliverability.
AI Email Summary
An AI email summary is a short, machine-generated overview of an email's key points, shown by Gmail, Outlook and Apple Mail before a recipient opens the message. It is reshaping how email marketers think about subject lines, preview text and open rates.
Alt Text
Alt text is the written alternative to an image in an email, displayed when images are blocked, slow to load, or consumed by screen readers.
AOL Mail for Email Marketers
AOL Mail is a legacy email provider with specific deliverability requirements and rendering quirks, now operating as part of the Yahoo+AOL network under shared infrastructure.
ARPU (Average Revenue Per User)
ARPU (Average Revenue Per User) is a metric that measures the average revenue generated per email subscriber over a specific period, used to evaluate list value and campaign effectiveness.
Frequently Asked Questions
Email deliverability rate is the percentage of sent emails that reach the intended inbox rather than bouncing or landing in spam. It measures whether your mail actually gets to the reader.
Any accepted email is delivered technically, but deliverability means it lands in the inbox where it is seen. An email accepted yet filtered to spam is delivered at the server but fails deliverability because it never reaches the recipient's view.
Low deliverability usually reflects reputation, authentication, list quality or engagement problems — such as high bounces or complaints, missing SPF/DKIM/DMARC, or a list full of inactive addresses. Addressing these raises the inbox rate.
Clean the list to remove bounces and disengaged contacts, authenticate your sending with SPF, DKIM and DMARC, keep content relevant to boost engagement, and monitor complaint rates to keep spam reports low.