Inbound

Inbound Email Processing

Receive, parse, and route incoming email. Webhooks, forwarding, storage, or drop. No size limits.

The Challenges

Why Inbound email is hard

Building Your Own Is a Nightmare

MX records, SMTP servers, MIME parsing, attachment handling, bounce management. Months of work before you process your first email.

Existing Solutions Are Limited

Resend only offers webhooks. Postmark restricts inbound to higher tiers. SendGrid's parse webhook has a 30MB limit and no routing control.

Inbound Is an Afterthought

Most providers bolt on inbound as a premium feature. You end up paying for a sending platform just to receive email.

The Solution

How Transmit helps Inbound Email Users

Four Actions, Full Control

Every inbound email hits your rules: webhook (HMAC-signed), forward (with attachments), store (searchable), or drop. Per-address routing with wildcard support.

No Size Limits

Our pipeline handles emails of any size. Attachments are preserved for forwarding. No 150KB cap like other providers, no 30MB parse limit.

Built Into the Platform

Inbound isn't an add-on. It's part of every plan. Same domain, same dashboard, same API. Send and receive through one integration.

Developer Experience

Handle Inbound Email via Webhook

Our API is built for the modern edge. No heavyweight SDKs, just simple REST and standard protocols.

Explorer documentation
example.javascriptjavascript
// Your endpoint receives parsed email via POST
app.post("/incoming-email", (req, res) => {
  const { from, to, subject, text, html, attachments } = req.body;

  // attachments[]: { filename, mimeType, size }
  // Full content available via API for forwarding

  if (to.includes("support@")) {
    createSupportTicket({ from, subject, text });
  } else if (to.includes("invoices@")) {
    processInvoiceEmail({ from, attachments });
  }

  res.sendStatus(200);
});

Other use cases

SaaS

Email Infrastructure for SaaS

The only email API aimed at multi-tenant SaaS platforms. Isolate tenant reputation automatically.

Developers

The Edge-Native Email API

Rest Email API built for the modern edge. Zero cold starts, global low latency, and open-source foundations.

Frequently Asked Questions

What inbound actions are available?
Four actions: webhook (POST to your URL with HMAC signature), forward (re-send with full attachments), store (save to searchable database), and drop (discard). Configure per-address or with wildcards.
Is there a size limit on inbound emails?
No. Emails are stored securely, then parsed. The pipeline handles attachments of any size, unlike providers capped at 150KB or 30MB (SendGrid).
Can I use inbound without sending?
Yes. Inbound is included in every plan. You can use Transmit purely for receiving and routing email if that's your use case.
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Ready to scale your Inbound email?

Start managed, upgrade to BYOK. Volume-based pricing starts at $2/month.