Lob Campaign Tracking

After sending postcards, track their delivery status through the Lob API. Lob provides USPS Intelligent Mail barcode tracking for letter-class mail, including postcards. Use this data to know when mail was delivered and correlate with inbound responses.

Retrieve a Single Postcard

curl https://api.lob.com/v1/postcards/psc_abc123 \
  -u "$LOB_API_KEY:"

Response (tracking fields)

{
  "id": "psc_abc123",
  "tracking_events": [
    {
      "id": "evnt_xyz",
      "type": "certified",
      "name": "In Transit",
      "time": "2026-04-02T14:30:00.000Z"
    },
    {
      "id": "evnt_abc",
      "type": "certified",
      "name": "Processed for Delivery",
      "time": "2026-04-04T08:15:00.000Z"
    }
  ],
  "expected_delivery_date": "2026-04-05",
  "send_date": "2026-04-01"
}

Tracking Event Types

• In Local Area — Mail is in the destination postal area
• In Transit — Mail is moving through USPS network
• Processed for Delivery — Mail is at the destination post office, out for delivery soon
• Re-Routed — Mail was redirected (address forwarding)
• Returned to Sender — Undeliverable, returned

List All Postcards (with filtering)

curl "https://api.lob.com/v1/postcards?limit=50&date_created=%7B%22gte%22%3A%222026-03-01%22%7D" \
  -u "$LOB_API_KEY:"

Filter parameters:

• limit — Number of results (max 100)
• offset — Pagination offset
• date_created — Filter by creation date range (use gte, lte)
• metadata[campaign_id] — Filter by custom metadata (if set at send time)

Webhook Events

Configure webhooks in the Lob dashboard to receive real-time delivery updates:

Dashboard URL: https://dashboard.lob.com/webhooks

Events you can subscribe to:

• postcard.created — Postcard entered the print queue
• postcard.rendered_pdf — PDF rendered, ready for printing
• postcard.rendered_thumbnails — Thumbnails generated
• postcard.deleted — Postcard canceled before printing
• postcard.delivered — Postcard marked as delivered by USPS
• postcard.in_transit — Postcard is in transit
• postcard.in_local_area — Postcard arrived in destination area
• postcard.re-routed — Postcard was rerouted
• postcard.returned_to_sender — Postcard returned to sender

Webhook Payload

{
  "id": "evt_abc123",
  "event_type": {
    "id": "postcard.delivered",
    "enabled_for_test": true
  },
  "body": {
    "id": "psc_abc123",
    "tracking_events": [ ... ]
  },
  "date_created": "2026-04-05T09:00:00.000Z"
}

Integration with n8n

Set up an n8n webhook node to receive Lob delivery events. When a postcard.delivered event fires:

1. Parse the postcard ID from the webhook payload
2. Look up the contact in Attio by the stored postcard ID
3. Update the contact's direct_mail_status field to "delivered"
4. Update direct_mail_delivered_date to the event timestamp
5. Start a 3-7 day timer — if no response by then, the postcard likely did not convert

Error Handling

| HTTP Code | Meaning | Action | |-----------|---------|--------| | 200 | Success | Process tracking data | | 401 | Invalid API key | Check credentials | | 404 | Postcard not found | Check the postcard ID |

Pricing

• Tracking is included with every postcard send at no additional cost
• Webhooks are free to configure

Notes

• USPS tracking for postcards is less granular than package tracking — you may only get 2-3 events total
• expected_delivery_date is an estimate; actual delivery can vary by 1-2 days
• Use the delivery date to set follow-up timers in your CRM — trigger a digital follow-up (email/LinkedIn) 3-5 days after confirmed delivery
• Attach metadata to postcards at send time (e.g., metadata[campaign_id]=dm-q2-2026) to make filtering and reporting easier