Email metrics reference
Complete reference for all metrics available for Email (transactional and marketing). All metrics in this reference apply to Email only.
Includes: Volume and delivery, engagement (opens and clicks), failure (bounces, dropped, suppressed), feedback (unsubscribes, complaints), and inbound metrics.
Quick reference
| Metric | API syntax | Key use |
|---|---|---|
| Total traffic | TOTAL_TRAFFIC_COUNT | Total outbound email volume |
| Total accepted | TOTAL_ACCEPTED_TRAFFIC_COUNT | Outbound emails accepted for processing |
| Total sent | TOTAL_SENT_TRAFFIC_COUNT | Emails submitted to the mailbox provider |
| Delivered | DELIVERED_TRAFFIC_COUNT | Emails successfully delivered to recipients |
| Delivery rate | TRAFFIC_DELIVERY_RATE | Delivery success rate |
| 5-second delivery rate | TRAFFIC_DELIVERED_IN_5_SEC_RATE | Percentage of emails delivered within 5 seconds |
| Unique opens | SEEN_OPENED_TRAFFIC_COUNT | Unique recipients who opened the email |
| Open rate | SEEN_OPENED_TRAFFIC_RATE | Percentage of delivered emails opened by unique recipients |
| Total opens | VIEWED_TOTAL_COUNT | All open events including re-opens by the same recipient |
| Total open rate | VIEWED_TOTAL_RATE | Open rate counting re-opens |
| Unique clicks | UNIQUE_CLICKS_COUNT | Unique recipients who clicked a link |
| Unique click-through rate | UNIQUE_CLICK_THROUGH_RATE | Percentage of unique recipients who clicked, relative to delivered |
| Unique clicked URLs | UNIQUE_URL_CLICK_COUNT | Number of unique URLs clicked in a single email |
| Click-to-open rate | CLICK_TO_OPEN_RATE | Percentage of recipients who clicked, relative to unique opens |
| Total clicks | TOTAL_CLICKS_COUNT | All link clicks including repeats |
| Click rate | TOTAL_CLICK_RATE | Total clicks divided by delivered emails |
| Bounced | TOTAL_BOUNCE_COUNT | Total bounces (soft + hard) |
| Bounce rate | TOTAL_BOUNCE_RATE | Percentage of sent emails that bounced |
| Soft bounce | SOFT_BOUNCE_COUNT | Temporary delivery failures |
| Hard bounce | HARD_BOUNCE_COUNT | Permanent delivery failures |
| Dropped | TOTAL_DROPPED_COUNT | Emails dropped before any delivery attempt |
| Dropped rate | TOTAL_DROPPED_RATE | Percentage of emails dropped before delivery |
| Suppressed | TOTAL_SUPPRESSED_COUNT | Emails blocked due to prior bounce or complaint history |
| Unsubscribes | UNSUBSCRIBED_USER_COUNT | Recipients who opted out |
| Unsubscribe rate | UNSUBSCRIBED_USER_RATE | Percentage of delivered emails that resulted in an opt-out |
| Spam complaints | EMAIL_COMPLAINTS_COUNT | Emails reported as spam |
| Spam complaint rate | EMAIL_COMPLAINTS_RATE | Percentage of delivered emails reported as spam |
| Received traffic | TOTAL_RECEIVED_TRAFFIC_COUNT | Inbound emails received from customers |
Volume and delivery metrics
| Metric | API syntax | Definition | Calculation |
|---|---|---|---|
| Total traffic | TOTAL_TRAFFIC_COUNT | The total number of emails sent to your customers (outbound) | Delivered + Failed + Pending |
| Total accepted | TOTAL_ACCEPTED_TRAFFIC_COUNT | The total number of emails accepted for processing by the platform (outbound only) | Delivered + Bounced + Dropped + Retried + Pending |
| Total sent | TOTAL_SENT_TRAFFIC_COUNT | The total number of emails sent from the platform to the mailbox provider | Delivered + Bounced + Retried |
| Delivered | DELIVERED_TRAFFIC_COUNT | The total number of emails delivered to a recipient | Sent − Bounced |
| Delivery rate | TRAFFIC_DELIVERY_RATE | The percentage of emails successfully delivered to recipients | (Delivered / Total sent) × 100 |
| 5-second delivery rate | TRAFFIC_DELIVERED_IN_5_SEC_RATE | The percentage of emails delivered within a 5-second time frame | (Delivered in under 5 seconds / Delivered) × 100 |
Failure metrics
| Metric | API syntax | Definition | Calculation |
|---|---|---|---|
| Bounced | TOTAL_BOUNCE_COUNT | The total number of emails not delivered to recipients, including soft bounces (temporary failures) and hard bounces (permanent failures) | — |
| Bounce rate | TOTAL_BOUNCE_RATE | Percentage of sent emails that bounced | (Bounced / Total Sent) × 100 |
| Soft bounce | SOFT_BOUNCE_COUNT | The number of emails temporarily undeliverable to recipients, such as when the inbox is full, the domain is temporarily unavailable, or the mailbox provider suspects legitimacy issues or lack of opt-in | — |
| Soft bounce rate | SOFT_BOUNCE_RATE | Percentage of sent emails that soft bounced | (Soft Bounces / Total Sent) × 100 |
| Hard bounce | HARD_BOUNCE_COUNT | The number of emails that received a permanent error from mailbox providers when attempting delivery to a specific recipient | — |
| Hard bounce rate | HARD_BOUNCE_RATE | Percentage of sent emails that hard bounced | (Hard Bounces / Total Sent) × 100 |
| Dropped | TOTAL_DROPPED_COUNT | The submitted emails dropped before delivery due to various reasons: the recipient unsubscribed, address bounced, message marked as spam, or sender errors (blocked or unverified domain) or content issues (expired templates, too many URLs) | Total traffic − Delivered − Bounced − Retried − Pending |
| Dropped rate | TOTAL_DROPPED_RATE | Percentage of emails that were dropped before delivery | (Dropped / Accepted) × 100 |
| Suppressed | TOTAL_SUPPRESSED_COUNT | Emails not sent due to prior bounce history or negative recipient reaction | — |
NOTE
FAILED_TRAFFIC_COUNT is not retrievable for Email. Use TOTAL_DROPPED_COUNT for counts of emails that failed to deliver. When a metric is not available for a channel, the Metrics API returns the literal string N/A as the value.Engagement metrics
| Metric | API syntax | Definition | Calculation |
|---|---|---|---|
| Unique opens | SEEN_OPENED_TRAFFIC_COUNT | The number of unique recipients who opened the email, counting each recipient only once regardless of how many times they opened the same message | — |
| Open rate | SEEN_OPENED_TRAFFIC_RATE | The percentage of delivered emails opened by unique recipients | (Unique Opens / Delivered) × 100 |
| Total opens | VIEWED_TOTAL_COUNT | All open events including re-opens by the same recipient | — |
| Total open rate | VIEWED_TOTAL_RATE | Percentage of delivered emails that were opened, counting re-opens | (Total Opens / Delivered) × 100 |
| Unique clicks | UNIQUE_CLICKS_COUNT | The number of unique recipients who clicked on any link within an email, counting each recipient only once regardless of the number of links clicked | — |
| Unique click-through rate | UNIQUE_CLICK_THROUGH_RATE | The percentage of unique recipients who clicked on a link compared to the total number of emails delivered, counting each recipient only once | (Unique Clicks / Delivered) × 100 |
| Unique clicked URLs | UNIQUE_URL_CLICK_COUNT | The number of unique URLs clicked in a single email | — |
| Click-to-open rate | CLICK_TO_OPEN_RATE | The percentage of recipients who opened the email and then clicked a link. Each recipient is counted once. | (Unique Clicks / Unique Opens) × 100 |
| Total clicks | TOTAL_CLICKS_COUNT | The total number of clicks on all URLs within a single email, including multiple clicks on the same link. Every URL click is counted except the unsubscribe link. | — |
| Click rate | TOTAL_CLICK_RATE | The percentage of recipients who clicked on any link, calculated as total clicks across all URLs divided by total delivered emails | (Total Clicks / Delivered) × 100 |
Feedback metrics
| Metric | API syntax | Definition | Calculation |
|---|---|---|---|
| Unsubscribes | UNSUBSCRIBED_USER_COUNT | The number of recipients who unsubscribed (opted out) from future communications sent from the sending address | — |
| Unsubscribe rate | UNSUBSCRIBED_USER_RATE | The percentage of recipients who unsubscribed (opted out) from future communications sent from the sending address | (Unsubscribed / Delivered) × 100 |
| Spam complaints | EMAIL_COMPLAINTS_COUNT | The number of emails that recipients reported as spam | — |
| Spam complaint rate | EMAIL_COMPLAINTS_RATE | The percentage of emails that recipients reported as spam | (Complaints / Delivered) × 100 |
Inbound metrics
| Metric | API syntax | Definition | Calculation |
|---|---|---|---|
| Received traffic | TOTAL_RECEIVED_TRAFFIC_COUNT | The total number of emails received from customers (inbound) | — |
Aggregation dimensions
All standard dimensions (time, geography, account, status) from the Metrics API apply to Email. The API always includes CHANNEL_CODE in results for metric accuracy, even if you do not specify it in aggregateBy. The following dimensions are particularly relevant for Email analysis:
| Dimension | Description |
|---|---|
SENDER_DOMAIN | Groups results by sender domain |
RECIPIENT_DOMAIN | Groups results by recipient domain |
TIME_TO_OPEN_FROM_DELIVERED | Groups results by time between delivery and an email being opened, using time buckets |
TIME_TO_CLICK_FROM_DELIVERED | Groups results by time between delivery and a link being clicked, using time buckets |
Related pages
Metrics API
Query these metrics programmatically alongside messaging and voice data through a single endpoint.
Analyze dashboard
View these metrics through the web interface with filters and visualizations.
Email deliverability center
Monitor domain and IP reputation, and analyze deliverability performance.
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