---
title: SMTP pooling
description: Reuse SMTP connections and apply shared rate limits.
icon: Network
source: "src/core/types.ts"
---

<Callout title="The one rule">Enable pooling only for a long-lived process that sends more than one message.</Callout>

```ts
import { createSMTPMailer } from "sently/smtp";

const mailer = await createSMTPMailer({
  host: "smtp.example.com", pool: true, maxConnections: 5, maxMessages: 100,
});
```

| Option | Default |
| --- | --- |
| `maxConnections` | 5 |
| `maxMessages` | 100 |
| `rateLimit` | 1000 ms |

<Cards><Card title="SMTP transport" href="/docs/transports/smtp" /></Cards>