MailToAPI vs Postmark Inbound
Both deliver inbound emails to your webhook. Postmark gives you the raw parsed email payload; MailToAPI gives you the extracted JSON fields you actually want. Here's the gap and when each fits.
TL;DR
- Postmark Inbound is a mature inbound email infrastructure product. It POSTs you a parsed-email JSON payload (from, to, subject, body html/text, headers, attachments) — but you still have to parse the body yourself to get structured fields.
- MailToAPI uses an LLM on top of inbound email infrastructure. You describe the JSON shape (
name,email,phone, etc.), forward an email, get that exact JSON POSTed to your API. - Postmark is the right floor if you want to build the parser yourself. MailToAPI is the right shortcut if you don't.
Feature comparison
MailToAPI
Postmark Inbound
What lands on your webhook
The exact JSON shape you defined (typed fields)
Raw parsed email JSON (you still parse the body)
Body parsing
Built-in LLM extraction against your schema
None — you write it yourself
Format drift handling
Usually tolerated automatically (LLM)
Your problem — your parser breaks when format changes
Setup
Describe schema, forward sample, done (5 min)
Set up MX records, configure inbound stream, write your parser (hours)
Attachments
Not in v1 — email body only
Yes — included in the payload
Pricing
$39/mo for 1,000 deliveries
Bundled with Postmark sending; inbound has a generous free tier
Reliability / maturity
Newer product, focused on extraction
Very mature transactional infrastructure
Agent / API setup
OpenAPI + agent skill
Manual dashboard config
Where each one wins
Choose MailToAPI when
- You want extracted JSON fields, not raw email payloads
- You don't want to maintain an email body parser as your product grows
- Emails come from many senders with varying formats
- You want an AI agent (Claude / GPT) to set up inboxes via API
- You don't already use Postmark for sending
Choose Postmark Inbound when
- You already use Postmark for sending — one vendor, one bill
- You need attachment handling out of the box
- You're confident your parsing logic will be tiny (one fixed format)
- You want raw email metadata (headers, full HTML body) for downstream tooling
- Compliance requires no LLM in the data path
Quick decision
If you'd be writing a body parser on top of whatever inbound provider you pick, MailToAPI replaces that work. If you genuinely want the raw email payload to do your own thing — Postmark Inbound is excellent and probably cheaper at volume.