---
title: "Mailers"
description: "What a BooleanSMTP mailer connection is, the five providers you can add today, and how to manage your connections."
image: "https://booleansmtp.com/docs/og.png"
---

> Documentation Index
> Fetch the complete documentation index at: https://booleansmtp.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Mailers

import { Aside } from '@booleanpress/nimbus/components';

A **mailer** in BooleanSMTP is a connection: one mail provider, its credentials, and the sender
details your site uses when it sends through that provider. Every email your site sends — contact
forms, password resets, order receipts — goes out through whichever connection BooleanSMTP resolves
for it, instead of your web server's own mail setup.

## Pick a mailer

Five providers are ready to connect:

| Mailer | How it sends | Best for |
| --- | --- | --- |
| [Amazon SES](/docs/mailers/ses/) | HTTPS API or SMTP | High-volume sending at low cost |
| [Google Workspace](/docs/mailers/google/) | Gmail API (OAuth) or SMTP (app password) | Business email already on Google |
| [Microsoft Outlook](/docs/mailers/outlook/) | Microsoft Graph API only | Business email already on Microsoft 365 |
| [Custom SMTP](/docs/mailers/smtp/) | SMTP, to any server you configure | Your host's mail server, or a provider not listed here |
| [PHP Mail](/docs/mailers/php/) | Your server's own `mail()` function | Local testing, or a last-resort fallback |

The **Choose a Mailer** screen currently lists these five providers.

Not sure which of the five fits your site? See [Which mailer should I use?](/docs/learn/choose-a-mailer/).

## Manage your connections

Add a connection under **BooleanSMTP → Mailers → Add Connection**. The first one you add during
setup becomes your primary connection; add a second under **Settings → Fallback Connection** so
BooleanSMTP has somewhere to retry a failed send.

![The Mailer Connections list in BooleanSMTP, with the Add Connection button and the Provider, Sender, Mode, Status, Health and Actions columns.](../../../assets/screenshots/mailers-list.webp "Mailer Connections list")

## What each row shows

Each row covers one connection, from **Provider** on the left to **Actions** on the right. Hide the
**Sender**, **Mode** or **Health** columns you don't need with the **Columns** button described
below; **Provider**, **Status** and **Actions** always show.

**Provider** shows the connection's icon, the name you gave it, and the provider it uses underneath
it, such as **Amazon SES** or **Google Workspace**.

### Default and fallback badges

An amber star next to a connection's name means it's the **Default Connection** in **Settings →
Delivery & Reliability**: the one BooleanSMTP uses when nothing more specific claims the message. A
blue lifebuoy icon means it's the selected **Fallback Connection**, retried once when the primary
send fails. Hover over either icon for details, including a warning if the connection is inactive
(an inactive connection is skipped for automatic sending even while assigned this way) or, on the
fallback badge, if fallback is currently turned off in Settings. Change either assignment on the
[Settings References](/docs/settings/) page; you can't reassign them from this list.

**Sender** shows the connection's **From Email**, with its **From Name** underneath in italics, or
*Not configured* if you haven't set one yet. If two connections on your site share a From address
because one was saved before BooleanSMTP's one-address-one-connection rule existed, a short warning
appears here explaining which connection actually handles mail for that address; see
[One connection per sender](/docs/advanced/one-connection-per-sender/).

**Mode** shows how the connection sends: a clock icon for **SMTP**, a lightning bolt for **API**, or
an envelope for **PHP** (your server's built-in `mail()` function).

### Check a Google or Outlook connection's sign-in status

For a Google Workspace or Microsoft Outlook connection sending over its API, hover over (or tap) the
**API** badge to see its OAuth sign-in status:

| Tooltip | What it means |
| --- | --- |
| Token valid (46m left), or Token valid (3h left) | The connection's current access token is still good for that long. |
| Token expired | The stored token has expired; BooleanSMTP needs a fresh sign-in before it can send. |
| No refresh token | Google or Microsoft didn't return a token BooleanSMTP can use to renew access on its own. |
| Token expiry unknown | BooleanSMTP has a refresh token on file but no recorded expiry for it yet. |

![The API mode badge on a Microsoft Outlook connection, with its OAuth token status shown in a tooltip.](../../../assets/screenshots/mailers-list-oauth-tooltip.webp "OAuth token status tooltip")

To fix an expired or missing token, open the connection with the pencil icon under **Actions** and
reconnect the account.

**Status** is the **Active**/**Inactive** switch. Turning off a connection currently assigned as the
Default or Fallback Connection asks you to confirm first: its Settings assignment stays saved, but
automatic email skips it until you turn it back on; another active connection takes over as default
if one exists, and an assigned fallback stops being tried immediately.

**Health** shows the result of the connection's last check: **Healthy**, **Error**, or **Unknown**
for one BooleanSMTP hasn't checked yet. Active connections are checked automatically on a regular
schedule, and immediately whenever you send a Quick Test or Test Email through one. Hover over a red
**Error** status to see the error message from that check.

## Test, edit or delete a connection

Use the icons under **Actions**:

- **Quick Test**, the paper plane icon shown only on active connections, opens a small dialog to
  send a real test email through that connection, addressed to your own account's email by default.
  It's recorded in [Email Logs](/docs/logs/) like any other send.
- **Edit**, the pencil icon, opens the connection's settings, including reconnecting an expired
  OAuth account.
- **Delete**, the trash icon, removes the connection once you confirm. This can't be undone.

> **Caution**
>
> Deleting a connection doesn't warn you first if it's currently assigned as your Default or Fallback
> Connection, the way switching it off does. Check [Settings References](/docs/settings/) before deleting
> one you're not sure about.

## Refresh status, add a connection, and choose columns

Above the table:

- **Refresh Status** reloads the list, including each connection's latest recorded status and
  health, without leaving the page.
- **Add Connection** opens the **Choose a Mailer** screen described above.
- **Columns** shows or hides the **Sender**, **Mode** and **Health** columns; **Provider**,
  **Status** and **Actions** always show.

If you have more connections than fit on one page, BooleanSMTP shows 10 per page by default. Use
**Rows per page** below the table to switch to 25, 50 or 100, and **Previous**/**Next** to move
between pages.

## Select and delete multiple connections

Check a row, or the checkbox in the header to select every connection, including ones on other
pages. The toolbar then switches to show how many are selected, with **Delete Selected** and
**Cancel**. **Delete Selected** asks you to confirm before removing all of them at once; this can't
be undone either.

![The Mailer Connections list with five connections selected, showing the Delete Selected and Cancel actions.](../../../assets/screenshots/mailers-list-bulk-select.webp "Bulk-selecting connections to delete")

## Next steps

- [Which mailer should I use?](/docs/learn/choose-a-mailer/)
- [One site, many senders](/docs/advanced/multiple-mailers/)
- [How a connection is chosen](/docs/advanced/how-a-connection-is-chosen/)
- [Settings References](/docs/settings/)
- [View email logs](/docs/logs/)

Source: https://booleansmtp.com/docs/mailers/index.mdx