---
title: "Sending testing emails"
description: "When a send button inside the Top Bar is clicked in editor preview, Topol converts the template to HTML and returns everything you need to send a test email."
url: https://docs.topol.io/email-editor/guide/sending-a-test-email.html
---

# Sending testing emails

**Pressing the send button in the editor preview converts the template to HTML and hands it to the `onTestSend` callback, which carries everything needed to send a test message through your own sender.**

```js
const TOPOL_OPTIONS = {
  callbacks: {
    onTestSend(email, json, html) {
      // send a testing email using your sender of choice
    },
  },
};
```

## Sending to multiple addresses

Setting the `testingEmails` option switches test sends into multi-recipient mode, where the preview shows a multi-select of saved addresses instead of a single input.

> **INFO**
>
> In multi-recipient mode `email` in the callback is always an array, even when only one address is selected.

### Emails saved in local storage

Setting `testingEmails` to `true` stores the recipient list in local storage, which keeps it across sessions on the same browser.

```js
testingEmails: true;
```

### Managing the addresses yourself

Setting `testingEmails` to an array seeds the editor with those addresses, up to a maximum of five (anything beyond the fifth is dropped).

```js
testingEmails: ["user1@example.test", "user2@example.test"];
```

In this mode, edits to the list are reported through the `updateTestingEmailAddresses` callback so the new list can be persisted server-side.

```js
const TOPOL_OPTIONS = {
  callbacks: {
    updateTestingEmailAddresses(emails) {
      // save the updated list to your DB
    },
  },
};
```