MailToAPI vs AWS SES Inbound
SES + Lambda is the cheapest inbound email pipeline at high scale — and the most work to assemble. MailToAPI gives you JSON-to-webhook in 5 minutes with no AWS to wire. Here's where each makes sense.
TL;DR
- SES Inbound uses receive rules — incoming mail can be saved to S3 and/or invoke a Lambda. You write Lambda code to parse the MIME, extract fields, and POST somewhere. Extremely cheap at scale, very flexible, very hands-on.
- MailToAPI is the hosted shortcut: describe the JSON shape, forward an email, the JSON lands on your API. No AWS, no Lambda, no MIME parsing.
- Pick SES Inbound when volume is huge and your team is comfortable with AWS infra. Pick MailToAPI when you want this working today and would rather not write a Lambda.
Feature comparison
MailToAPI
AWS SES Inbound
What you write
A JSON schema (declared in the UI or API)
A Lambda function that parses raw MIME and POSTs somewhere
What lands on your code
Your declared JSON, typed fields
Raw email (S3 object or Lambda event with MIME)
Body field extraction
Built-in LLM against your schema
You write it — regex, templates, or your own LLM call
Setup
5 minutes
Hours: verify domain, MX records, receipt rule set, S3 / Lambda permissions, parser, deploy pipeline
Pricing
$39/mo for 1,000 deliveries
~$0.0001 per email received + S3 / Lambda costs (~free at low volume)
Reliability
Service handles drift, retries, dead-letter
You build the retry / dead-letter logic in Lambda
Best volume range
Low-to-mid (tens to low thousands of emails / month)
High volume (tens of thousands to millions / month)
Data residency
Hosted by us (Railway region)
Your AWS account, your region
Where each one wins
Choose MailToAPI when
- You want to ship today, not next sprint
- You don't want to maintain a Lambda just to parse email bodies
- Email formats vary and your Lambda would need re-tuning constantly
- Volume is well under what makes a custom AWS pipeline pay off
- You want an AI agent (Claude / GPT) to set up inboxes via API
Choose AWS SES Inbound when
- Volume is high enough that per-email costs of any hosted service add up
- You already run on AWS and adding receipt rules is trivial
- Compliance requires email never leaves your AWS account
- You're comfortable owning the entire pipeline (parser, retries, dead-letter, monitoring)
- You want raw MIME for downstream tooling that needs it
Quick decision
Volume is the deciding factor. Under 5,000 emails/month, MailToAPI is cheaper than what an engineer spends building and maintaining the SES + Lambda pipeline. Over 50,000/month, SES + Lambda wins on raw cost — assuming you already have AWS muscle on the team.