Klaviyo experienced a minor incident on April 23, 2025 affecting Campaign Email Sending and Flow Email Sending, lasting 1h 47m. The incident has been resolved; the full update timeline is below.
Affected components
Campaign Email SendingFlow Email Sending
Update timeline
- investigating Apr 23, 2025, 10:06 PM UTC
Beginning around 5 PM US Eastern time, we began observing delays in email messages sent by a mail delivery partner. In addition to a subset of campaign and flow messages, this may affect emails for multi-factor authentication login and double opt-in emails. Mail is being accepted and processed, but is delayed; we do not expect data loss. We will provide further updates as we have them.
- resolved Apr 23, 2025, 11:53 PM UTC
We can confirm that all delayed emails have caught up as of approximately 7:15 PM US Eastern, and email sending is back to real time.