Microsoft 365 email integrations made easy

Seamlessly connect your application with Microsoft 365, Microsoft Outlook, and more using the Nylas Email API.

  • Easily integrate with Microsoft 365 and Outlook email
  • Master Microsoft’s authentication and verification process
  • Effortlessly simplify complex email integrations with Nylas

Build for free

Unlock your potential with Nylas and start building for free today. Experience the power of our robust APIs to streamline your development process and maintenance with integrations across providers.

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const Nylas = require('nylas');
Nylas.config({ clientId: CLIENT_ID, clientSecret: CLIENT_SECRET });
// Return all accounts connected to your Nylas App.
Nylas.accounts.list().then(accounts => {
    for (let account of accounts) {
        `Email: ${account.emailAddress} | `,
        `Billing State: ${account.billingState} | `
public class Email {
  public static void main (String[] args) throws Exception {
    NylasAccount account = new NylasClient().account(ACCESS_TOKEN);
    List threads = account.threads().list(
      new ThreadQuery().unread(true)); Thread thread ) -> { 
      System.out.println( thread.getSubject() ); 

from nylas import APIClient
client = APIClient(
# .all() returns all threads that have been synced to Nylas
threads = nylas.threads.all(limit=10) # Limit and offset can be used to control pagination
for thread in threads:
    print("Subject: {} | Participants: {}".format(
        thread.subject, thread.participants
require 'nylas'
nylas =
    app_id: CLIENT_ID,
    app_secret: CLIENT_SECRET,
    access_token: ACCESS_TOKEN
account = nylas.current_account
    "Email: #{account.email_address} | " \
    "Provider: #{account.provider} | " 

Connect to the Microsoft 365 REST API in minutes

The Nylas Email API gives you a secure, reliable connection to your users’ Microsoft 365 accounts, as well as every other email service provider (Gmail, Microsoft Exchange, and IMAP). With Nylas, you have a single point of integration connecting your app to your users’ inboxes, powering bi-directional email with 99.6% deliverability.

Integrate with the Microsoft 365 REST API faster with Nylas

Building a custom Microsoft 365 mail sync would take around 5,072 hours of your development team’s time. Connect to Microsoft 365 and any other provider in a fraction of the time with Nylas.


Bi-directional sync and full CRUD

With Nylas, user’ email data syncs bi-directionally between their Microsoft 365 email account and your app. With full CRUD (create, read, update, delete) capabilties, you can build full-featured email capabiltiieswithin your application.


Webhook notifications

Webhooks allow your application to receive notifications when certain events occur — they are easy to integrate with your app and scale seamlessly with your growth.


99.9% guaranteed uptime

Nylas sends mail through the account’s original SMTP/ActiveSync gateway, which means messages sent through Nylas have high deliverability.

Avoid the considerable cost of a custom Microsoft 365 Email integration

The costs of integrating Microsoft 365 email or any other provider on your own increase considerably as your platform and user base grow. Consider the following: 

  • Delivering expanded functionalities such as advanced email analytics 
  • Added infrastructure requirements
  • Increased maintenance and support demands
  • Enhanced security requirements
  • Scalability challenges

The Nylas Email API helps control costs associated with email integration by abstracting away the resource-insensive process of building and maintaing integrations. By connecting to 100% of service providers using a secure, scalable API, we help you refocus your developers on building core features.

With Nylas, your Microsoft 365 integration is secure, scalable, and performant

At Nylas, we prioritize security and seamless integration for your Microsoft 365 integration. Trust us to handle every detail while ensuring your data remains secure.

  • Nylas holds industry-leading security certifications, including SOC 2, Privacy Shield, GDPR compliance, and HIPAA readiness
  • We employ robust token management techniques to ensure secure and authorized access to your Microsoft 365 email data
  • Our system allows only authorized IP addresses to interact with your Microsoft 365 integration, providing an additional layer of security
  • Every email you sync is encrypted to safeguard your sensitive information from unauthorized access
  • We have highly customizable authentication scopes, allowing you to define precise permissions for accessing Microsoft 365 email data
  • Our multi-level permission checks ensure that only authorized users can access and modify your Microsoft 365 integration settings
Download the Security Whitepaper

Ready to integrate Microsoft 365 API in your app?

Discover the power of the Nylas platform and connect up to 5 accounts for free.

Frequently Asked Questions

What is Microsoft 365 Email API integration?

Microsoft 365 Email API integration refers to the process of connecting and integrating Microsoft 365 (formerly known as Office 365) email services with other applications or systems using the Microsoft 365 Email API.

The Microsoft 365 Email API provides developers with a set of tools, protocols, and functions to programmatically interact with Microsoft 365 email services, such as sending and receiving emails, managing folders, accessing calendars, and retrieving contact information.

By integrating the Microsoft 365 Email API into their applications or systems, developers can enable functionalities that involve email communication and collaboration, allowing users to seamlessly interact with their Microsoft 365 email accounts directly from within other applications.

What is the difference between Microsoft 365 Email API, Exchange Email API, and the Outlook Email API

The Microsoft 365 Email API provides a comprehensive interface to access Microsoft 365 services, while the Exchange Email API focuses on integration with on-premises Exchange Server. The Outlook Email API is specifically designed for web-based interactions with Each API serves different purposes and targets specific integration needs within the Microsoft ecosystem.

How do I integrate Microsoft 365 Email API with other apps or services?

Integrating the Microsoft 365 Email API with other apps or services allows for seamless communication and collaboration between Microsoft 365 email and external platforms. Follow these steps to get started:

  1. Register your application in the Azure portal to obtain the necessary credentials
  2. Authenticate your app and obtain an access token using OAuth 2.0 or another supported authentication flow
  3. Configure the required permissions and consent in the Azure portal
  4. Familiarize yourself with the Microsoft 365 Email API documentation to understand its endpoints and operations
  5. Use the obtained access token to make requests to the API endpoints, such as retrieving emails or sending new ones
  6. Handle API responses and errors in your application code
  7. Thoroughly test your integration and iterate as needed

With Nylas, you can simplify this process —  sign up for a developer account and start building for free. 

What programming languages can I use to integrate the Microsoft 365 Email API?

The Microsoft 365 Email API can be integrated using various programming languages, including JavaScript/Node.js, Python, C#, Java, Ruby, and PHP. The choice of programming language depends on your familiarity, project requirements, and the ecosystem of your application or service.