Building Ghost Inbox: How We Wired Resend + Discord Into a Full Two-Way Customer Messaging System

Every small business owner knows the chaos of a shared inbox. Emails get missed. Replies come from personal accounts. Nothing is tracked. Ghost Inbox is our answer. When a customer emails your business address, Resend captures the inbound and fires a webhook to our Ghost Inbox API route. We parse the sender, subject, and body, save it to the contact_submissions table, and create a Discord thread inside your private server. You reply in Discord — like any other message. The Discord bot catches your reply and fires back through Resend with the proper In-Reply-To header so the customer sees a clean email thread. The whole thing runs on Railway as a persistent process. No third-party CRM. No per-seat licensing. One system, fully owned. Every message is logged in the dashboard. Every thread is searchable. Every reply is timestamped. This is the kind of infrastructure that used to require a $300/mo tool. We built it into the platform at no additional cost.