Why is my email flow not sending?

Find where the expected email stopped before changing the flow. Check the contact’s trigger evidence, the individual message’s status and its recipient activity. Waiting, manual review, a deliberate skip and a delivery failure require different responses. Verify future sends separately from missed messages: turning a message live does not automatically clear its manual-review backlog.

Start with an affected contact and the particular email they should have received. “The flow is live” is too broad a diagnosis when each message has its own status.

The interface examples below use Klaviyo marketing email flows. Apply the investigation to another tool only after checking its own status meanings and recovery rules.

Locate the last recorded step

Use the recipient-activity definitions to separate these cases:

The Recipients bucket means targeted recipients, including unsuccessful deliveries. Do not read it as the delivered count.

For a recorded delivery failure, use the hard-versus-soft bounce guide. For questions about folder placement after sending, follow the deliverability investigation.

If the contact never entered, inspect the trigger evidence

For a list- or segment-triggered flow, check the exact connected list or segment and whether new qualifying contacts are reaching it. Check the form’s destination too. Similar list names are not proof of the same destination.

The documented list/segment troubleshooting path also offers trigger → Preview to inspect profile-filter results. Use the failed condition to narrow the investigation. Our welcome-flow explainer covers the separate question of what event should start a welcome journey.

For an event-triggered flow, identify the triggering metric, then inspect that event on the affected profile. Open its activity menu and Activity details to compare when the event happened with when the platform recorded it.

The metric-flow troubleshooting guide says a recording delay of at least 6 hours prevents an event from triggering a metric-based flow. Flows marked transactional have a separate allowance of up to 7 days. These are documented product rules, not a general standard for how quickly integrations should sync.

If the message is live, check its previous status too

In this implementation, Draft messages do not send or queue contacts. Manual messages queue for review. Live enables automatic sending for eligible contacts at the configured time.

The message-enablement guide gives the individual-message path: select the message card, check its content and settings, then choose Live from its status dropdown. A bulk status update still leaves unconfigured actions in Draft.

Crucially, changing Manual to Live does not automatically send messages already in Needs Review.

Consider this invented timeline, not an account test:

A successful new send would therefore leave a separate backlog decision. Open message → Performance → View details → Recipient activity → Needs Review, as the list/segment troubleshooting guide describes. Review the pending message and choose whether to send or cancel it. Sending manually still skips a contact who no longer meets the flow filters.

If the contact was skipped, decide whether the exclusion was correct

Open message → Performance → View details → Recipient activity → Skipped. Use Type to inspect the reason and affected profiles in the skip-reason report.

A checkout-recovery email skipped after a purchase can be the intended result. Restore an expected send without removing that safeguard; the abandonment handoff guide covers stage exclusions.

Other reasons point elsewhere: a missing address or suppression concerns the contact; template syntax and external-data errors concern message construction; exhausted uploaded coupons concern a content dependency; an account sending limit concerns sending capacity. Check the stated cause rather than editing the trigger for each case.

For Smart Sending, check recent email activity and the configured email window. The frequency-control documentation separates channels and applies the control to marketing messages. An email skip is not evidence of a cross-channel frequency cap.

It also states that Smart Sending skips are not automatically rescheduled. Do not treat that record as a delayed message still waiting to go out. Decide separately whether a later send is appropriate.

Verify the repair and retain the result

If sending stopped after previously working, inspect View flow history in the flow-builder header. The history records what changed, who changed it and when, using the account’s timezone. Compare it with the affected contact’s timeline; a nearby edit is a lead to investigate.

Keep this proposed repair record:

For verification, run a permitted test journey expected to send and another expected to be excluded. Compare actual recipient activity with both expectations. These are suggested checks, not tests we ran on a store.

Then revisit the old affected contact. A new send establishes that the new journey worked; it does not establish that an earlier queued or skipped message was resolved. Record both outcomes before closing the incident.

Why is a live flow email still in Needs Review?

In Klaviyo, a message queued while its status was Manual remains in Needs Review after the message changes to Live. Review that existing item and send or cancel it separately. A manual send still checks flow-filter eligibility.

Will an email skipped by Smart Sending go out later automatically?

No. Klaviyo does not automatically reschedule messages skipped by Smart Sending. Check whether another send is still appropriate; do not count a frequency skip as a message waiting for its window to expire.

Does a skipped email mean the flow is broken?

Not necessarily. A contact can fail a flow or message-specific filter at send time; for example, a purchase exclusion can correctly skip a checkout reminder after the shopper buys. Other reasons, such as a template syntax error or an error retrieving external data, indicate a problem with the message. Read the recorded reason and compare it with the intended rule.