n8n Workflow: Verify Mailing Address Deliverability

This n8n workflow provides a robust solution for verifying the deliverability of mailing addresses. It acts as a webhook endpoint, receiving address data, processing it, and then performing a verification check using an external API. The workflow includes logic to handle different verification outcomes, allowing for conditional subsequent actions.

What it does

1. Listens for Incoming Data: The workflow starts by exposing a webhook endpoint, ready to receive address data from an external source (e.g., a CRM, a form submission).
2. Edits and Prepares Data: It then uses an "Edit Fields (Set)" node to transform or prepare the incoming data, likely extracting relevant address components for the verification API.
3. Performs Address Verification: An "HTTP Request" node is used to send the prepared address data to an external address verification API (e.g., Lob, USPS, etc.).
4. Routes Based on Verification Status: A "Switch" node evaluates the response from the address verification API. This allows the workflow to take different paths based on whether the address is deliverable, undeliverable, or requires further attention.

Prerequisites/Requirements

• n8n Instance: A running instance of n8n to import and execute the workflow.
• External System: An external system (e.g., Groundhogg, a custom application) capable of sending HTTP POST requests to the n8n webhook.
• Address Verification API: Access to an address verification API (e.g., Lob, SmartyStreets, USPS API) with appropriate API keys and endpoints. The "HTTP Request" node will need to be configured with the specific API details.

Setup/Usage

1. Import the Workflow: Import the provided JSON into your n8n instance.
2. Configure Webhook:
   • Open the "Webhook" node.
   • Note down the "Webhook URL". This is the endpoint your external system will send data to.
   • Set the "HTTP Method" to POST (or as required by your sending system).
3. Configure Edit Fields (Set) Node:
   • Open the "Edit Fields (Set)" node.
   • Adjust the fields to extract and transform the incoming data from the webhook into the format required by your address verification API.
4. Configure HTTP Request Node:
   • Open the "HTTP Request" node.
   • Set the "Method" (likely POST).
   • Enter the "URL" of your address verification API endpoint.
   • Configure "Headers" (e.g., Content-Type: application/json, Authorization: Bearer YOUR_API_KEY).
   • Set the "Body Parameters" to send the address data, referencing the output from the "Edit Fields (Set)" node using expressions (e.g., {{ $json.street_address }}).
5. Configure Switch Node:
   • Open the "Switch" node.
   • Define the "Value" to evaluate based on the response from the "HTTP Request" node (e.g., {{ $json.delivery_status }}).
   • Add "Cases" for different verification outcomes (e.g., "deliverable", "undeliverable", "unknown").
   • Connect subsequent nodes to each case to define actions for each outcome (e.g., update contact in CRM, send notification, log error).
6. Activate the Workflow: Once configured, activate the workflow in n8n.
7. Trigger from External System: Configure your external system to send a POST request with contact address data to the n8n webhook URL.