Send to your whole audience from the same server and IP that delivers your receipts and password resets. No separate broadcast product, no per-contact tax, no second sender identity to warm up. Build an audience, drop in a template, schedule it, ship.
Audiences, templates, scheduling, and unsubscribe handling are built into the same platform as your API sends — sharing the same domains, DKIM keys, dedicated IP, and suppression list.
Group contacts into audiences, import via CSV or the API, and segment who gets what. Every send writes back opens, clicks, bounces, and unsubscribes to the contact record — no external CRM required.
The same templates power both your broadcasts and your transactional API. Merge contact fields for personalization, preview against real records, and version changes so a bad edit never ships to the whole list.
Fire immediately or schedule for a future time in any timezone. Large sends drain through your dedicated IP at a managed rate so a 700K broadcast lands cleanly instead of tripping throttles.
Because broadcasts leave from the same dedicated IP and authenticated domain as your transactional mail, your campaign inherits a warmed, trusted sender identity from day one. Managed warm-up and automatic SPF, DKIM, and DMARC keep it there.
Every broadcast ships with a compliant List-Unsubscribe header and one-click opt-out. Unsubscribes, hard bounces, and spam complaints flow into a single suppression list that both broadcasts and your API respect — automatically, on every future send.
Grow your list to a million people and pay nothing extra to store them. You pay for emails that actually go out, the same way your transactional sends are metered. Compare how the marketing tax stacks up.
| mailstein | Typical ESP | |
|---|---|---|
| Broadcasts and transactional on one platform | Yes | Separate product |
| Marketing billed per send | Yes | Per contact stored |
| Shared IP & reputation across both streams | Yes | Separate sender |
| One suppression list for all mail | Yes | Per-product lists |
| Logs & contacts on your own server | Yes | Their cloud |
| Pay to store non-sending contacts | Never | Yes |
Broadcasts aren't a bolted-on UI — they're first-class in the REST API, SDK, CLI, and MCP. Target an audience, attach a template, set a schedule, and let mailstein handle rate-managed delivery through your own IP. The same primitives your agents already use for transactional mail.
Free covers 50 emails a month and 1 domain — no card. Send your first broadcast from infrastructure that's actually yours.
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