Master Inbox
Integrations and Webhooks

Troubleshoot Webhooks, Workflows, and Automation Failures

When webhooks stop firing, workflows skip actions, or reminders and outbound queues stall, the root cause is usually in the configuration—event filters, trigger conditions, or connection health. This guide walks through diagnosing the most common webhook and workflow failures.

Before You Start

Most automation failures fall into one of these categories:

  • Webhook not firing — The event happens in Master Inbox, but your endpoint never receives the payload.

  • Workflow not running — A trigger fires but actions don't execute, or only some actions complete.

  • Label-change events missing — Labels change in the inbox but webhooks or workflows don't respond.

  • Reminder webhooks not firing — Reminders become due but no webhook or workflow triggers.

  • Outbound queue backed up — Actions to external tools (Smartlead, Instantly, Heyreach, etc.) queue but don't complete.

Work through the relevant section below for your specific symptom.

Webhook Not Firing

If your webhook endpoint isn't receiving events, check these points in order:

1. Verify the Webhook Is Active

Go to Settings → locate your webhook and confirm it shows as Active. Inactive webhooks do not send events.

2. Confirm the Event Type Matches

Webhooks listen for specific event types. If you're expecting a webhook on a label change but the webhook is configured for Message Incoming, it won't fire.

Available event types:

  • Message Incoming — Fires when a prospect replies.

  • Message Outgoing — Fires when you send a reply.

  • Reminder Triggered — Fires when a reminder becomes due.

  • Label Changed — Fires when any label is added or removed.

  • Email Disconnected — Fires when an email channel disconnects.

  • Prospect List Updated — Fires when a conversation moves between lists.

Edit your webhook and verify the event type matches the behavior you're tracking.

3. Check Channel, View, and Label Filters

Webhooks can be narrowed by Channels, Views, and Labels. If filters are set, the webhook only fires when all filter conditions match.

Example: A webhook set to Label Changed with a filter for Label = Interested will only fire when the "Interested" label is specifically added or removed—not for other label changes.

To test:

  1. Temporarily remove filters and trigger the event.

  2. If the webhook fires without filters, the issue is filter mismatch.

  3. Re-add filters one at a time to isolate the restrictive condition.

4. Test Your Endpoint Independently

Use a tool like Postman or curl to send a test POST request to your webhook URL. If your endpoint doesn't respond, the issue is on your infrastructure side—not Master Inbox.

5. Verify Payload Expectations

Review the payload structure for the event type you're using. Ensure your endpoint parses the expected fields correctly.

Common mismatches:

  • Expecting email but the message is a LinkedIn reply (no email address).

  • Expecting a specific label_names value but labels are an array.

  • Looking for subject on a LinkedIn thread (subject only exists for email).

Label-Change Webhooks Not Firing

If label changes aren't triggering webhooks or workflows, check:

1. Distinguish Label Change vs. Label Assignment

The Label Changed event fires when a label is added or removed from a conversation. If you're expecting a webhook when a label is "assigned" but the label was already present, no event fires.

2. Verify the Label Exists and Is Correct

Open Labels from the left menu and confirm the label name matches exactly what's in your webhook filter. Labels are case-sensitive.

3. Check Whether a Reply Exists

Labels can be applied to conversations regardless of whether a prospect has replied. If your webhook filters expect a reply to exist (e.g., filtering by Views that only show replied threads), the webhook may not fire for label changes on unreplied conversations.

Related: How to Create a Label

Reminder Webhooks Not Firing

Reminders have two related trigger types:

  • Reminder Triggered (webhooks) — Fires when a reminder becomes due.

  • Due Reminder (workflows) — Fires when a reminder becomes due.

  • New Reminder (workflows only) — Fires when a reminder is created.

Common Issues

  • Wrong trigger type: If you're using a webhook and expecting it to fire when a reminder is created, it won't—webhooks only support Reminder Triggered, which fires at the due time.

  • Reminder not yet due: The webhook only fires at the moment the reminder time passes. Check the reminder time on the conversation.

  • Reminder already completed or dismissed: If a user marks a reminder done before it fires, the event may not trigger.

To test, create a new reminder set to fire in 1–2 minutes and observe whether the webhook fires at the due time.

Workflow Not Running or Incomplete

Workflows execute actions when triggers fire and conditions match. If a workflow isn't behaving as expected:

1. Verify the Workflow Is Active

Go to Settings → Workflows and confirm the workflow toggle is set to Active. Inactive workflows do not execute.

2. Check the Trigger Type

Match the trigger type to the event you expect:

  • Add Label / Remove Label — Fires on label changes.

  • Incoming Message — Fires on prospect replies.

  • Sending Message — Fires when you send a reply.

  • Message Seen — Fires when a message is viewed.

  • Move to List / Removed from List — Fires on list changes.

  • Due Reminder / New Reminder — Fires on reminder events.

  • Meeting Booked / Rescheduled / Cancelled — Fires on calendar events.

  • Found Phone Number — Fires when a phone number is detected.

  • Incoming Webhook — Fires when an external system sends data in.

3. Review Trigger Options

Trigger options narrow the trigger to a specific item. For example, Add Label as a trigger type shows all labels in trigger options—you must select the correct label for the workflow to fire on that label.

4. Verify Conditions

Conditions filter when the workflow runs after the trigger fires. If conditions are too restrictive, the workflow may not run even though the trigger fired.

Check conditions like:

  • Channel — Is the event coming from the expected channel?

  • Labels — Does the conversation have the expected labels?

  • Read Status — Is the message read/unread as expected?

Temporarily remove conditions to test if the workflow runs.

5. Check Workflow Logs

From the workflow list, open the ⋯ menu and select View Logs. Logs show:

  • Execution history

  • Which triggers fired

  • Whether conditions were met

  • Which actions executed

6. Understand Action Failure Behavior

Workflows execute actions in the order they're added. If one action fails, other actions may still run, but the workflow may not complete fully.

Common causes of action failure:

  • Outbound tool not connected — The workflow tries to send to Smartlead, Instantly, or Heyreach but the integration is disconnected.

  • Invalid label or list — The workflow references a deleted label or list.

  • CRM sync error — HubSpot integration issues prevent sync.

Check workflow logs to see which actions completed and which failed.

Outbound Queue Backed Up

When workflows trigger actions in outbound tools (Smartlead, Instantly, Heyreach, Email Bison), those actions are queued for delivery. If outbound actions are stalling:

1. Verify the Outbound Tool Connection

Go to Settings → Integrations and confirm the outbound tool (Smartlead, Instantly, Heyreach, or Email Bison) shows as Connected.

If the connection shows an error or requires re-authentication, reconnect it.

2. Check API Limits on the Outbound Tool

Outbound tools may have API rate limits. If Master Inbox hits those limits, outbound actions queue until the limit resets. Check the outbound tool's dashboard for API usage or errors.

3. Verify Campaign/Sequence and List References

Workflows reference specific campaigns, sequences, or lists in outbound tools. If those were deleted or renamed in the outbound tool, actions may fail silently.

Open the workflow and confirm the selected campaign/sequence still exists in the outbound tool.

4. Review Workflow Logs

Workflow logs indicate whether outbound actions were queued or failed. If logs show failures, the issue is likely the connection or the referenced resource.

Monitoring and Debugging

In-App Notification Center

The Notification Center surfaces system events including webhook delivery issues and integration errors. Check here for alerts about:

  • Email channel disconnections

  • Integration failures

  • System-level issues affecting automation

Workflow Logs

For workflow-specific issues, workflow logs are the primary debugging tool. They show whether triggers fired, conditions matched, and which actions executed or failed.

External Logging

For webhooks, maintain logs on your endpoint side. Log incoming requests including:

  • Timestamp

  • Event type

  • Payload body

  • Response status code

This helps determine whether webhooks are arriving but being processed incorrectly, or not arriving at all.

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