Robert Willson

Posted on Jun 9

Agentic Commercial Hub : Postmark Challenge

#devchallenge #postmarkchallenge #webdev #api

This is a submission for the Postmark Challenge: Inbox Innovators.

What We Built

The Agentic Commercial Hub is an email automation platform that transforms customer replies to transactional emails into intelligent, contextual conversations. Our system integrates Postmark's Inbound email processing with 3rd party APIs/tools and Know Reply's agents to create a fully automated customer service experience that scales small businesses without losing the personal touch.

The Problem We Solve
The “Agentic Commercial Hub” helps businesses systematize operations leading to more satisfied customer interactions and less lost sales opportunities. The Hub is an intelligent bridge between customer emails and business systems, providing instant, accurate, contextually-aware responses that feel completely human.

Illustrative scenario
Meet Jack, who runs a boutique travel agency specializing in ski vacation packages in Niseko, Japan. As Niseko has exploded in popularity, Jack's one-person operation is drowning in customer emails. Every booking generates dozens of follow-up questions: "Can I change my boot size?", "What's included in ski lessons?", "Where can we go for dinner?", "What time is check-out?"

Jack spends 6+ hours daily answering repetitive questions, can only respond during business hours, and often makes errors when tired. Meanwhile, customers like Alice wait 4-24 hours for responses, sometimes needing to email multiple times to get complete answers across timezones.

Now with the Agentic Commercial Hub, customer replies are automatically read, understood, acted upon in the order system, and replied to immediately. Alice gets the answers she needs without waiting and Jack can focus on managing his business...and maybe even getting in a few ski days himself.

Demo

🌐 Demo Sites Built for Inbox Innovators Challenge Submission:

Demo Travel Agency: Know Snow - Niseko Adventures built on WordPress & WooCommerce
Agentic Commercial Hub: https://hub.knowreply.email

Alice: The customer's workflow:
These steps are required to get an email you can interact with for the demo

Alice decides to book a vacation at Know Snow - Niseko Adventures
Click "Packages" and then "Book Now"

Fill in the purchase form using the email address you want to test with (use test credit card 4242 4242 4242 4242 any future expiry date like "09/26" and any CVC number like "123")

Click "Place Order"

The system will send an Order Confirmation email to you via a Postmark Transactional stream

Now you can now reply to this email with any questions about your order, Niseko area, activities, etc.
Interact with the agent via email by replying with questions like "Where can we find daycare in the area? Please update my rental boots size to 9".

You will get quick replies and your order will be updated in WooCommerce and visible in your Orders page if you click on the order after getting your reply email.

Jack: The business owner's workflow:
Jack can log into the Agentic Commercial Hub and monitor customer interactions with his company emails and agents. Analytics are derrived from customer email interactions

Login: jack@test.knowreply.email
Password: 1q2w3e4r

Quick KPIs at a glace

Activity by Topics (transactional email subject lines and even campaign emails) and Agents (Inbound Streams). Customer trends, types of emails received, customer FAQs, etc

Customers: Select a customer and deep dive into their emails, questions, sentiment, and results

Jack can also see updates to orders in WooCommerce sorry, no account provided as that could break the demo

Administrator: The setup workflow
How an administrator would setup and manage their Agentic Commercial Hub configuration. Keep using Jack's demo account, but editing is disabled

Postmark Setup tab:
Inbound and Outbound email setup

Postmark Server API Configuration: This token allows the system to send replies from your Postmark managed email account
Inbound Email Webhook Configuration: This is the webhook assigned to you and should be added to Postmark's Inbound Stream settings

Agent Tools Setup tab:
Here you can configure your API tokens for WooCommerce and other connected services (others are not implemented yet)

Add a Connection: This will list registered MCP services. Each requires API tokens (eg. your Stripe, WooCommerce, Active Campaign etc)
Select tools from the Connection you want your agents to be able to use (eg. we use createOrderNote in WooCommerce to update order details and the other tools to identify each customer and their order)

Each tool can be tested as long as you've entered your API token for that service. Click the pencil icon to test and enter JSON data like a customer's email address to look up their customer id

Know Reply Setup tab:
Know Reply is the service where the Agent's personality and knowledge base is setup.

Add the API token for your account and it will list your configured agents
Select the agents you want to enable, the email accounts they will get Inbound emails from, and which Agent Tools will be available to them. This allows for multiple agents with different abilities for different needs.

Email Testing

Here you can simulate customer emails without going through the full workflow of triggering transactional emails and sending replies. It's a faster way to test and doesn't use your Postmark credits
Create different scenarios by adding a New Test Case and modifying the Inbound email JSON sample. Test different languages, Spam flags, error handling, etc.

After a test is complete you can review the system output and resulting customer email

Activity Logs

See ALL emails that have been processed by the system (including test emails). Click on any email to see the Inbound JSON, Connected Tools Called (what was called and why), the Return Email

External Tools Used for Inbox Innovators Challenge

These are not part of submission but required for app to work
Know Reply

Here we set up our Agent's personality/role

Give it a knowledge base all about Niseko and the agency's services
Here we get our API token for the Agentic Commercial Hub configuration

Postmark Transactional & Inbound Streams

Here is where you can setup your Inbound webhook URL as provided in the Agentic Commercial Hub setup screen
Here is where you can get your API tokens for sending emails via the Transactional Stream

Code Repository

How We Built It

System Flow
Our integration follows this workflow:

Customer orders something a WooCommerce store
Customer receives a confirmation (transactional) email via Postmark x WooCommerce
Customer Replies to the transactional email
Postmark Inbound → Captures email, parses content, sends JSON to our Agentic Commercial Hub webhook
Hub Validation → Verifies legitimate customer email using spam flags and sender validation
Connected Tools planner → LLM analyzes email content and determines required actions and which connected tools it can use
Tool Execution → Uses known input values from the email and chains tools together, feeding the output from one into another (eg. get customerId from email address, look-up orders with customerId, finds the orderId needed, updates order using orderId)
Send the email contents and Tool Execution results to Know Reply to generate a contextually-aware response using customer data + business knowledge
Returns email draft to the Hub. Stores analytics for reporting
Hub calls Postmark to send the customer response

Tech Stack
Integration Layer:

Node.js/Express for webhook processing and API orchestration
Postmark Inbound API for email parsing and spam detection
MCP Protocol for agent communication and tool execution. We plan to migrate to Anthropics MCP model SDK architecture as a next step when fully integrating this Hub. We had some issues getting it working and in the interest of time, built our own API wrappers
Stripe & WooCommerce MCP Server wrapped REST API for customer and order management. This is extensible to add many more connectable MCP server integrations (eg. Hubspot, ActiveCampaign, SFDC, Zendesk, etc)

AI & Logic:

Know Reply AI Platform for contextual response generation
Google Gemini for MCP planning and content analysis
Custom Knowledge Base containing travel agency expertise

Infrastructure:

Hostinger hosted Wordpress with WooCommerce and Stripe backend for demo travel agency site
Vercel and Supabase for hosting the Agentic Commercial Hub site Google Cloud for MCP server processing and Gemini API

Postmark Integration Experience

Working with Postmark for both Inbound and Transaction email processing has been so easy:

JSON webhook format makes parsing customer emails straightforward and so much easier than going directly into inboxes
Instead of polling inboxes for new emails, the instant delivery of emails into a webhook is blazingly fast
Spam detection headers help us easily filter legitimate customer inquiries
Reliable delivery ensures our AI responses reach customers immediately
The bidirectional email flow (Transaction Email → Inbound Reply → Processing → Outbound via API) creates a seamless customer experience that feels like emailing a human assistant.

Small businesses like travel agencies and WooCommerce stores are the backbone of specialized industries, but they can't compete with large corporations on customer service responsiveness. Our integration brings enterprise-level customer service automation, allowing boutique businesses to provide superior experiences while maintaining their personal touch and specialized expertise.

About Us

We made Know Reply as an AI-driven communications company specializing in context-aware email automation for small and medium-sized businesses. Our platform uses advanced AI agents to understand, act on, and respond to customer emails with human-like accuracy—always within the full context of our client’s business.

We believe, like Postmark, that email should be a channel for genuine connection, trust, and value—not noise. Our mission is to restore the personal, human touch to business email by making every reply meaningful and relevant. By transforming transactional and “no-reply” inboxes into responsive, intelligent conversations, Know Reply helps businesses build lasting relationships with their customers—one authentic message at a time.

Through this integration, we see Know Reply as amplifying Postmark’s core values: delivering email that is fast, reliable, and truly wanted by recipients.