Diagnosing missing Instantly replies
When to use this guide: Use this when a rep saw a reply but HubSpot or OutboundSync webhook logs show no Email Reply for that contact.
OutboundSync syncs what Instantly sends. If Instantly never logged the reply or emitted a Reply received webhook, OutboundSync has nothing to process.
1. Rule out a HubSpot visibility issue
Section titled “1. Rule out a HubSpot visibility issue”Each HubSpot user must enable OutboundSync timeline events once: open a contact → Activities → Filter activity → check OutboundSync. See Contact timeline events in HubSpot.
If webhook logs already show EMAIL_REPLY, visibility — not sync — is the problem.
2. Confirm Instantly webhooks
Section titled “2. Confirm Instantly webhooks”In Settings → Integrations → Webhooks, verify:
- The OutboundSync endpoint covers All campaigns (or the campaign in question).
- Reply received is toggled on.
- No other webhook URL replaces OutboundSync for the same events.
See the Instantly webhook guide for the full checklist.
3. Search OutboundSync webhook logs
Section titled “3. Search OutboundSync webhook logs”- Open History → Webhooks in OutboundSync.
- Search by the contact’s email.
- Clear the Event Type filter so you see all payloads for that lead.
See How to check OutboundSync logs if you need a refresher on the log UI.
What the logs mean
Section titled “What the logs mean”EMAIL_REPLY is present — OutboundSync received the reply. If HubSpot still looks wrong, recheck Filter activity (step 1) or see Data in OutboundSync but not my CRM for category filters and Update Only.
Only EMAIL_SENT and LEAD_CATEGORY_UPDATED — Instantly did not send a reply event. OutboundSync cannot recreate it.
Open the category payload. When a sequence ends without a reply, Instantly often sends LEAD_CATEGORY_UPDATED with a label like campaign completed for lead without reply. That is expected for leads who never replied — not proof that a manual reply synced. Many of these events alongside EMAIL_SENT usually means webhooks are working.
Why Instantly may not capture the reply
Section titled “Why Instantly may not capture the reply”- Reply not in Unibox — the rep saw it via auto-forward or a mailbox outside Instantly.
- Reply-to mailbox permissions — the address was added but permissions were not accepted before the reply arrived.
- Different reply address — the prospect replied from an email other than the one enrolled in the campaign.
- Early setup — the reply arrived before webhooks or mailbox setup was finished.
In Instantly, search the lead list, review campaign activity, and check Unibox. If the reply is not in Unibox, Instantly likely did not emit a webhook. For the related duplicate-contact pattern on Smartlead, see When new address replies create duplicates.
Escalation
Section titled “Escalation”Ask Instantly support whether the reply exists in their system and which mailbox received it. If both Instantly and OutboundSync logs lack a reply event, email service@outboundsync.com with screenshots from both systems.
