Searching for the Microsoft 365 SMTP settings, also known as the Office 365 SMTP settings?

Microsoft 365, formerly known as Office 365, is a subscription service from Microsoft that gives you access to a suite of features, including email hosting.

With the SMTP details for Microsoft 365, you can configure your email client or WordPress website to send emails using your Microsoft 365 account.

If you configure your preferred email client, this means you can send emails directly from the email client instead of needing to use your Microsoft 365 webmail. And if you configure your WordPress site to use these credentials, you can make your WordPress emails more reliable and fix the WordPress emails not sending problem.

This post starts off by quickly sharing the Microsoft 365 SMTP settings, as well as the POP3 and IMAP settings (which let you receive emails, whereas SMTP is for sending emails). This article also shows you how to configure your WordPress site to send emails using Microsoft 365.

Because Microsoft still uses both Microsoft 365 and Office 365 on its websites, we’re going to use these terms interchangeably in this article. The current name as of 2021 is “Microsoft 365”, but you still see the term “Office 365” a lot, including in the actual SMTP server credentials.

What are the Microsoft 365 / Office 365 SMTP settings?

If you’re in a hurry, let’s jump right into the Office 365 SMTP settings:

  • SMTP Server — smtp.office365.com
  • Port: 587 (learn more about SMTP ports)
  • Requires SSL — Yes
  • Requires TLS — Yes (if available)
  • Authentication — Yes (choose Login if multiple options available)
  • Username — Your full Microsoft 365 email address (e.g. [email protected])
  • Password — The password associated with your Microsoft 365 email address. You or your Microsoft 365 admin entered this password when creating the email account.

What are the Microsoft 365 / Office 365 IMAP settings?

While the Office 365 SMTP server lets you send emails using Office 365, IMAP and POP3 let you receive emails that have been sent to your Microsoft 365 email account.

If you want to set up Microsoft 365 with an email client, you typically need to use either IMAP or POP3 credentials to receive email in addition to the Office 365 SMTP server for email sending.

Overall, IMAP is the better choice if you plan to access emails from multiple devices because it allows two-way syncing. However, POP3 can also work if you’re only using a single device.

The Office 365 IMAP settings are as follows:

  • Server — outlook.office365.com
  • Port — 993
  • Encryption method — TLS
  • Username — Your full Microsoft 365 email address (e.g. [email protected])
  • Password — The password associated with your Microsoft 365 email address.

What are the Microsoft 365 / Office 365 POP3 settings?

If you’d prefer to use POP3 over IMAP, you can use the following credentials:

  • Server — outlook.office365.com
  • Port — 995
  • Encryption method — TLS
  • Username — Your full Microsoft 365 email address (e.g. [email protected])
  • Password — The password associated with your Microsoft 365 email address.

Microsoft 365 / Office 365 SMTP FAQs

Let’s quickly run over some frequently asked questions about Microsoft 365’s SMTP.

Does Office 365 allow SMTP relay?

Yes, you can use Microsoft 365/Office 365 as an SMTP relay. In the next section, we show you how you can send your WordPress site’s transactional emails using the Office 365 SMTP server.

You can also create connectors to send emails with the Office 365 SMTP relay.

How do I use Office 365 as SMTP?

By default, Microsoft 365 disables SMTP authentication (SMTP AUTH). However, you can easily enable it with just a few clicks from your Microsoft 365 admin center. The next section shows you how to do this in detail.

Once you enable SMTP AUTH client submission, you can set up email sending by entering the SMTP server details from above.

How to configure Microsoft 365 / Office 365 SMTP for WordPress sites?

In addition to using the Office 365 SMTP server to configure your email client, you can also use it to send your WordPress site’s transactional emails, which can improve their reliability and fix any issues you have with WordPress emails not sending.

Best of all, you can do this at no extra cost using your existing Microsoft 365 subscription.

This section shows you step-by-step how to set this up using the free Post SMTP WordPress plugin.

If you have any issues with this guide, it’s worth pointing out that you can find lots of other free SMTP servers to make your WordPress emails more reliable. We also have step-by-step guides on how you can configure some of the most popular options:

But before you resort to any alternatives, let’s go through how to set up the Microsoft 365 SMTP server with WordPress.

1. Enable SMTP Authentication in Microsoft 365

In order to send your WordPress site’s emails via your Microsoft 365 email address, you first need to enable SMTP authentication for that email address in your Microsoft 365 admin center. Otherwise, Microsoft 365 will block requests to the SMTP server.

To get started, open the Active users tab in your Microsoft 365 admin center. You can click here to open the right page or expand the hamburger icon in the top-left corner of the admin center and go to Users > Active users.

Then, click on the email account that you want to use to send your WordPress site’s emails. This expands a slide-out with more options.

In the slide-out, go to the Mail tab. Then, click the Manage email apps option.

How to open SMTP settings in Microsoft 365 admin center.
How to open SMTP settings in Microsoft 365 admin center.

Check the box for Authenticated SMTP in the list of options. Then, click the Save changes button at the bottom.

How to enable the Authenticated SMTP setting.
How to enable the Authenticated SMTP setting.

And that’s it! You’re done working in the Microsoft 365 admin center – everything else is done from your WordPress dashboard.

It’s also possible to authenticate Microsoft 365 SMTP connections using OAuth, though this adds some complexity to the process. For most casual users, the easiest option is to just enable Authenticated SMTP. More on this at the end of this tutorial.

2. Install and configure Post SMTP plugin

Once you’ve enabled Authenticated SMTP in your Microsoft 365 admin center, open your WordPress site and install the free Post SMTP plugin from WordPress.org.

Post SMTP lets you configure your WordPress site to send its emails using any SMTP server. In this case, that’s the Office 365 SMTP server.

Once you’ve activated the plugin, go to the new Post SMTP area in your WordPress dashboard and click the Start the Wizard button.

How to launch the Post SMTP setup wizard.
How to launch the Post SMTP setup wizard.

In the Sender Details tab, enter the Microsoft 365 email address that you want to use as your Email Address. This should be the same account for which you just enabled Authenticated SMTP in the previous step.

For the Name, enter the name that you want people to see when they receive emails from your site:

Where to enter your Microsoft 365 sender details in the plugin's settings.
Enter your Microsoft 365 sender details.

On the next screen, enter smtp.office365.com as the Outgoing Mail Server Hostname and then click Next.

Where to enter the Microsoft 365 SMTP server hostname.
Enter the Microsoft 365 SMTP server hostname.

Post SMTP will now run a connectivity test, which might take a few seconds. Once it finishes, it suggests the optimal settings:

  • Choose SMTP under the Socket setting.
  • Choose Password under the Authentication setting.

These should both be selected by default.

You need to verify that Post SMTP detected the proper settings.
Verify that Post SMTP detected the proper settings.

On the next screen, you are prompted to enter your username and password:

  • Username – the full email address of the Microsoft 365 email account that you want to use.
  • Password – the password associated with this Microsoft 365 email address. If you forget your password, you can reset it from the Microsoft 365 admin center.
Where to enter the username and password for your Microsoft 365 email account.
Enter the username and password for your Microsoft 365 email account.

On the last step of the setup wizard, you can optionally configure notifications to have Post SMTP alert you if it ever has a problem sending emails via Microsoft 365. If you don’t want to enable notifications, you can just click the Next button to skip these.

Post SMTP lets you configure notifications, but these are totally optional and you can skip this test.
Configure notifications if needed (optional).

3. Send a test email

To make sure your configuration is working properly, Post SMTP includes a feature that lets you send a test email.

To access this, go to the Post SMTP area in your dashboard and click the Send a Test Email link.

How to send a test email with Post SMTP.
How to send a test email with Post SMTP.

On the next screen, enter your email address. This is the email address to which Post SMTP will send the test email.

Enter the email address to which you want to send the test email.
Enter the email address to which you want to send the test email.

If your configuration is working, you should see a success message on the next screen.

Verify that your test email was sent.
Verify that your test email was sent.

You should also receive a test email at the email address that you entered.

If the test email worked, that’s all!

If it didn’t, proceed to the next section for a few troubleshooting tips.

Troubleshooting issues with Microsoft 365 SMTP on WordPress

If you have issues configuring your WordPress site to send emails via the Microsoft 365 SMTP server, the first thing you want to do is double-check all of the details. When you’re working with passwords and port numbers, it’s easy to make a typo and even minor typos can cause big issues.

If that doesn’t fix the problem, you can try digging into Post SMTP’s email log to see more specific issues. You can access this by going to Post SMTP > Email Log.

For example, in the first two requests in the screenshot below, you can see an error message that says “Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant.”

An example of the error message when you haven't enabled Authenticated SMTP.
An example of the error message when you haven’t enabled Authenticated SMTP.

If you see this error message, it means that you haven’t enabled SMTP authentication for this email address in your Microsoft 365 admin console.

Go back to the first step in this guide and make sure that SMTP authentication is enabled for the email account that you’re trying to use on your WordPress site.

If Post SMTP is able to successfully send the email but you’re not receiving it in your email client, it’s possible that it’s getting flagged as spam. If this is happening to you, make sure that you’ve set up a custom domain name in Microsoft 365 and properly authenticated it for email, including setting up DKIM.

While we used Microsoft 365’s default onmicrosoft.com subdomain in the screenshots above, you don’t want to use this subdomain on a real site because Microsoft 365 filters/throttles emails sent via the subdomain. Setting up a custom domain name should fix any remaining issues that you’re having with deliverability.

Another option – Use OAuth instead of SMTP authentication

In addition to using the Office 365 SMTP server, you can also configure WordPress to send emails using Office 365 and OAuth.

As we mentioned earlier, this is a bit more complex, but it might be worthwhile if you’re having issues with basic SMTP authentication.

The Post SMTP plugin doesn’t currently support using OAuth with Microsoft 365 (though the developer is working on an add-on for this feature), but you can find other plugins that do:

The complex part of this approach is that you need to use Microsoft Azure to create a custom application before you can set up the connection. Azure is Microsoft’s cloud platform – it’s similar to Google Cloud and AWS.

Both plugins above include documentation that shows you how to set this up.

Summary

With the Microsoft 365/Office 365 SMTP server, you can configure email clients, your WordPress site, or other applications to send emails using your Microsoft 365 email account.

For WordPress users, configuring your site to send its email via Microsoft 365 can help you improve the reliability of your site’s emails. If you’re already paying for Microsoft 365, this can be a great way to get some extra value from your subscription.

Remember that Microsoft 365 disables SMTP authentication by default, so you need to enable it for each mailbox that you want to use via the Microsoft 365 admin center. Or, you can also connect via OAuth instead of entering the SMTP server details directly.