---
title: Legacy API (sunsets 2027-06-01)
slug: legacy-api
docTags: 
createdAt: 2026-06-16T03:07:41.730Z
---

:::hint{type="warning"}
## These APIs sunset on June 1, 2027

The pages in this section document the **original mailfloss API** (`api.mailfloss.com/...?api_key=`). It is deprecated and will be retired on **June 1, 2027**. Build new integrations on the [v1 API](https://developers.mailfloss.com/quickstart) and migrate existing ones before the sunset date.
:::

The original mailfloss API is split into three areas, each with a v1 successor:

- **Email Verification API** — verify single addresses. → v1 [`/v1/verify`](https://developers.mailfloss.com/quickstart)
- **Integration Settings API** — manage connected ESP settings. → v1 `/v1/integrations`
- **Data Privacy API** — erase stored verification records. → v1 `/v1/erasures`

Authentication also changed: the legacy `?api_key=` query parameter is replaced by a Bearer token in v1. See the v1 [Authentication](https://developers.mailfloss.com/authentication) guide for the one-line migration.