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SparkPost events are tracked with specific event type IDs in SendPost, allowing you to distinguish between native SendPost events and SparkPost events.

SparkPost Event Types

Event TypeIDSparkPost EventDescription
SP Sent37injectionEmail accepted by SparkPost for delivery
SP Delivered38deliveryEmail successfully delivered to recipient
SP Deferred39delayTemporary delivery delay (SparkPost will retry)
SP Dropped40policy_rejectionEmail dropped by SparkPost policy
SP Hard Bounced41bounce, out_of_bandPermanent delivery failure
SP Soft Bounced42(reserved)Temporary delivery failure
SP Opened43open, initial_openRecipient opened the email
SP Clicked44clickRecipient clicked a link
SP Spam Report45spam_complaintRecipient marked email as spam
SP Unsubscribe46list_unsubscribe, link_unsubscribeRecipient unsubscribed

Bounce Type Details

SparkPost categorizes bounces into different types:
Permanent failure (invalid email, domain doesn’t exist). Includes both synchronous bounce events and asynchronous out_of_band bounces. These addresses should be removed from your list.
Temporary failure. SparkPost may retry these automatically. Consider these as temporary issues.

SparkPost Bounce Classes

SparkPost provides detailed bounce classification via bounce_class:
Bounce ClassCategoryDescription
1UndeterminedUnable to classify
10Invalid RecipientHard bounce - invalid address
20Soft BounceTemporary failure
21DNS FailureTemporary DNS lookup failure
22Mailbox FullRecipient’s mailbox is full
23Too LargeMessage size too large
24TimeoutConnection timeout
25Admin FailureAdministrative failure
30Generic BounceNo RCPT permission
40Generic BounceNetwork error
50Mail BlockBlocked by recipient
51Spam RelatedBlocked as spam
52Spam ContentContent flagged as spam
53Prohibited AttachmentAttachment type blocked
60Auto-ReplyAuto-reply message
70Transient FailureTemporary system failure
80SubscribeSubscribe request
90UnsubscribeUnsubscribe request
100Challenge-ResponseChallenge-response system

Event Data

Each SparkPost event includes:
  • Message ID (for correlation)
  • Recipient email
  • Timestamp
  • SMTP response code (for bounces)
  • User agent (for opens)
  • Clicked URL (for clicks)
  • SparkPost-specific IDs (message_id, transmission_id)
  • Bounce class (for bounce events)
  • Geographic information (country, region, city)

Event Type Quick Reference

EventIDSparkPost Event Name
Sent37injection
Delivered38delivery
Deferred39delay
Dropped40policy_rejection
Hard Bounce41bounce, out_of_band
Soft Bounce42(reserved)
Open43open, initial_open
Click44click
Spam45spam_complaint
Unsubscribe46list_unsubscribe, link_unsubscribe

Next Steps