POSTBOX
A multi-tenant support-ticket system that turns a small business's website contact form and support email into one threaded inbox. The alternative for a small shop is a shared Gmail account where enquiries get lost, and the commercial helpdesks are priced and shaped for far larger teams.
The problem
A small business takes enquiries through two unrelated channels — a website contact form and a support inbox — with no shared history and no record of what was answered. The obvious fix, replying from the business's own domain, was not available: you cannot verify a domain you do not control, so mail sent as the client would fail authentication and land in spam. Replies had to originate from a domain I could verify while still threading correctly in the customer's mail client.
What I did
One Next.js application, with tenancy scoped per workspace. The email loop is the substance of it. Replies send from a verified domain as "Business Name" <replies@…>, with a per-ticket reply address, so a customer answering in their own mail client lands back on the right thread without the business needing to hand over their domain. Threading anchors on the customer's own Message-ID rather than one I mint, because the sending infrastructure overwrites custom ids — that detail took the longest to find and is the difference between a conversation and a pile of disconnected emails. Inbound mail arrives by signature-verified webhook, with bodies fetched separately since the webhook carries only metadata.