---
title: "Microsoft Exchange 365 Mailer"
manual: "Microsoft Exchange 365 Mailer"
version: "main"
permalink: "https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:start@main"
source: "Index.rst"
start: true
rendered: "2026-10-04T20:03:13+00:00"
---

# Microsoft Exchange 365 Mailer {#start}

-   *Extension key:* ok_exchange365_mailer
-   *Package name:* oliverkroener/ok-exchange365-mailer
-   *Version:* release
-   *Language:* en
-   *Author:* [Oliver Kroener](https://www.oliver-kroener.de) <[ok@oliver-kroener.de](mailto:ok@oliver-kroener.de)\>
-   *License:*

    This document is published under the
    [Open Publication License](https://www.opencontent.org/openpub/).

-   *Rendered:* today

---

A TYPO3 extension for sending emails via Microsoft Exchange 365 using the
MS Graph API instead of SMTP. Uses OAuth 2.0 client credentials flow for
secure, token-based authentication.

> [!WARNING]
> **Attention**
>
> Since **Q3 2025**, Microsoft has enforced stricter access policies in *some* Exchange 365 tenants. You may need to configure an **Application Access Policy** to restrict app permissions to specific mailboxes. See [Exchange Online Setup](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:exchange-setup@main).
>
> This can also be used to restrict sending to *only* specific sender addresses (e.g., a **shared mailbox**).

![Open book icon](/Images/Icons/introduction.svg)

**Introduction**

Learn what this extension does, its features, and system requirements.

[Learn more](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:introduction@main)

![Download arrow icon](/Images/Icons/installation.svg)

**Installation**

Install the extension via Composer and activate it in your TYPO3 project.

[Get started](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:installation@main)

![Layered versions icon](/Images/Icons/compatibility.svg)

**Compatibility**

Find the right extension version for your TYPO3 major — one release line per major.

[View matrix](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:compatibility@main)

![Cloud with key icon](/Images/Icons/azure.svg)

**Microsoft Entra ID Setup**

Register an app in Microsoft Entra ID (formerly Azure AD) and configure
API permissions for Graph API mail sending.

[Configure Azure](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:azure@main)

![Shield icon](/Images/Icons/exchange-setup.svg)

**Exchange Online Setup**

Configure Application Access Policies to restrict app permissions to
specific mailboxes using PowerShell.

[View guide](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:exchange-setup@main)

![Settings sliders icon](/Images/Icons/configuration.svg)

**Configuration**

Set up the extension via environment variables, TYPO3 settings, or
TypoScript for frontend form integration.

[Configure](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:configuration@main)

![Code brackets icon](/Images/Icons/development.svg)

**Development**

Architecture internals, the automated cross-version test matrix, and how to
contribute.

[Read more](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:development@main)

![Question mark icon](/Images/Icons/faq.svg)

**FAQ**

Answers to frequently asked questions about installation, configuration,
and usage.

[Read FAQ](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:faq@main)

![Envelope icon](/Images/Icons/contact.svg)

**Contact**

Get in touch with the author for support, questions, or contributions.

[Get in touch](https://docs.typo3.org/permalink/oliverkroener/ok-exchange365-mailer:contact@main)