> AI agents: this is one page from PostHog's docs. Full index of Markdown docs for LLMs: https://posthog.com/llms.txt

# Linking Postmark as a source

Canonical URL: https://posthog.com/docs/data-pipelines/sources/postmark

> **Cloud region:** This page uses US Cloud hosts. For an EU Cloud project, use `https://eu.posthog.com` instead of `https://app.posthog.com` (app host for links).

## On this page

- [Schemas](#schemas)
- [Adding a data source](#adding-a-data-source)
- [Sync limitations](#sync-limitations)
- [Configuration](#configuration)
- [Supported tables](#supported-tables)

![](https://res.cloudinary.com/dmukukwp6/image/upload/texture_tan_9608fcca70)

![](https://res.cloudinary.com/dmukukwp6/image/upload/texture_tan_dark_a92b0e022d)

Let AI connect your sources for you

Skip the manual setup — run this in your project and the wizard auto-detects your databases and APIs and connects them to PostHog.

`npx @posthog/wizard warehouse`

![PostHog Wizard hedgehog](https://res.cloudinary.com/dmukukwp6/image/upload/wizard_3f8bb7a240.png)

![](https://res.cloudinary.com/dmukukwp6/image/upload/wizard_3f8bb7a240.png)Let AI connect your sources for you

The Postmark connector syncs your transactional email data into PostHog, including outbound messages, inbound messages, bounces, templates, and message streams.

## Schemas

| Schema | Description |
| --- | --- |
| `messages_outbound` | Outbound email messages sent through Postmark |
| `messages_inbound` | Inbound email messages received through Postmark |
| `bounces` | Email bounces and delivery failures |
| `templates` | Email templates configured in your Postmark server |
| `message_streams` | Message streams for organizing email types |

## Adding a data source

1.  Go to the [Data pipeline page](https://app.posthog.com/data-management/sources) and select the **Sources** tab.
2.  Click **New source** and select Postmark.
3.  Enter your Postmark Server API token. You can find this in your Postmark dashboard under **Servers** > select your server > **API Tokens**.
4.  *Optional:* Add a prefix to your table names.
5.  Click **Next**.

The data warehouse then starts syncing your Postmark data. You can see details and progress in the [data pipeline sources tab](https://app.posthog.com/data-management/sources).

## Sync limitations

-   **Full refresh only** – Postmark syncs use full refresh mode. Incremental syncing is not currently supported.
-   **10,000 row limit** – The Postmark API caps each paginated endpoint at 10,000 rows. If you have more than 10,000 messages, bounces, or other records, only the most recent 10,000 are synced.
-   **Message retention** – Postmark expires messages after a retention window (45 days by default), so historical data beyond that window is unavailable from the API.

## Configuration

| Option | Type | Required |
| --- | --- | --- |
| `Server API token` | password | Yes |

## Supported tables

| Table | Description | Sync method | Incremental field | Primary key |
| --- | --- | --- | --- | --- |
| `messages_outbound` | An outbound email message sent through Postmark. | Full refresh | — | — |
| `messages_inbound` | An inbound email message received through Postmark. | Full refresh | — | — |
| `bounces` | A bounce record for an email that could not be delivered. | Webhook, Full refresh | — | — |
| `opens` | The first open of an outbound message by one recipient, recorded when open tracking is on. | Full refresh | — | — |
| `templates` | An email template defined in Postmark. | Full refresh | — | — |
| `message_streams` | A message stream that groups outbound or inbound messages in Postmark. | Full refresh | — | — |