Isolated IP pools, message logs that live on your own servers, and managed deliverability — transactional and broadcast on one platform, billed per send. No shared SES pool. No per-contact tax. No data leaving your perimeter.
Most email platforms are a thin API over Amazon SES — your reputation sits in a shared pool and your logs sit in someone else's account. mailstein runs on the Postal MTA under the hood and sends from your own IPs, so the parts that matter to a security team stay under your control.
Dedicated IP pools that are yours alone, with managed warm-up so a new sending IP ramps cleanly. Your deliverability reflects your mail — not the behavior of every other tenant sharing a provider's SES account.
Message logs, event history, and suppression data live on servers you run. When compliance asks where email content and metadata are stored, the answer is a system you control — not a vendor's data lake.
Domain authentication is configured and verified for you, with dedicated IPs and bounce/complaint suppression built in. Alignment is correct from the first send instead of a ticket six weeks into onboarding.
One platform for password resets, receipts, and product email — and for the newsletter, lifecycle campaign, and announcement blast. Billed per send, never per contact.
Dedicated IPs are warmed on a managed schedule, and hard bounces and complaints are suppressed automatically so a bad list can't torch your reputation.
Transactional and broadcast bill on the same per-send meter. A million-address audience you email once a month costs what one million sends cost — not a per-contact subscription that grows with a list you barely mail.
REST API, SMTP relay, templates, contacts and audiences, campaigns, domains, webhooks, suppressions, and analytics — plus SDK, CLI, and an MCP server so agents can send and query mail directly.
Run mailstein on your own servers for full data residency, or let us operate the control plane while mail still leaves from your dedicated IPs. Either way the reputation and logs are yours.
The developer experience is the clean, modern API teams want — while underneath, the message leaves from your dedicated IP and lands in a log you own. Onboarding pairs your team with ours to authenticate domains, provision IP pools, and validate deliverability before you cut over production traffic.
Isolated IP pools, logs on your own infrastructure, and a per-send bill that doesn't punish you for the size of your list. Start free — 50 emails a month and one domain, no card. Talk to us when you're ready to scale.
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