How to Create an Office 365 Mailbox

How to create an office 365 mailbox

This article will show you how to create an Office 365 mailbox in a hybrid environment using any of the three following methods:

  • Easy365Manager
  • Standard Microsoft Web Tools
  • Microsoft PowerShell

An Office 365 mailbox is created by assigning an Exchange Online license to the user. The process depends on what tool you’re using.

But in either case, it involves the following steps:

  1. Create a user account in your on-premises Active Directory
  2. Synchronize the user to Azure AD/Office 365
  3. Assign an Exchange Online license to the Office 365 user account

Create an Office 365 Mailbox Using Easy365Manager

Easy365Manager represents by far the easiest way to assign and manage Office 365 mailboxes and licenses.

Easy365Manager is a snap-in to Active Directory Users & Computers. This means you’re completing all steps from your AD management console.

Using the Easy365Manager snap-in, you can create both the on-premises user and the Office 365 user directly from your AD management console in a single step.

Once the user is created, open up user properties and select the Office 365 tab:

how to create a mailbox - user properties

Look for an Exchange Online license in the list of available licenses. You can easily browse and expand all your subscription plans in user properties. The number of available licenses, as well as the total number, can be seen directly.

Select an Exchange Online license or subscription plan and click Apply. That’s it!

No matter what tool you’re using, the mailbox provisioning in Exchange Online can take a minute or two. You can see the mailbox properties in the Mailbox tab of user properties when the mailbox has been created:

Create Office 365 mailbox

If you’re not already using Easy365Manager, you can read about all the features here.

You’ll find the fully functional 30-day trial here.

Create an Office 365 Mailbox Using Standard Tools

Using the standard tools is a fragmented experience.

You need the Active Directory Users & Computers – this is used to create the user account.

You’ll then need to manually synchronize the AD user to Office 365 using Azure AD Connect (or wait for up to 15 minutes for auto-replication to take place).

Then you need to log in to Microsoft Admin Center to assign the Exchange Online license:

Create Office 365 Mailbox from Microsoft Admin Center

Select active users, select the user, and click on Licenses and apps to view the available licensing plans. Notice that, unlike Easy365Manager, you can’t explore the service plans included in the various licensing plans. Therefore you can’t assign individual service plans, only entire licensing plans.

Once you select the Exchange Online license plan and click Save changes, the Office 365 mailbox is created.

To see and configure mailbox properties you must log in to yet another web console, the Exchange Admin Center. With the Easy365Manager snap-in all information and tasks are available directly in the AD Users & Computers tool.

You can download a free 30-day trial of Easy365Manager here.

Create an Office 365 Mailbox Using PowerShell

To create an Office 365 mailbox for an existing user using PowerShell you can use the Enable-RemoteMailbox command on your on-premises Exchange server:

Enable-RemoteMailbox "Tycho Brahe" -RemoteRoutingAddress "tycho.brahe@skrubbeltrang.mail.onmicrosoft.com"

This will create an Exchange Online mailbox with a grace period of 30 days. To keep the mailbox you will need to assign an Exchange Online license before expiration.

This can be done using the methods listed in the previous sections, but if you want to stick with PowerShell you can e.g. use the MSOnline module:

$LO = New-MsolLicenseOptions -AccountSkuId "skrubbeltrang:ENTERPRISEPACK" -DisabledPlans "SHAREPOINTWAC", "SHAREPOINTENTERPRISE"
Set-MsolUserLicense -UserPrincipalName tbr@skrubbeltrang.com -LicenseOptions $LO

Notice that an on-premises Exchange Server is needed to run Enable-RemoteMailbox.

Easy365Manager does not require an on-premises Exchange server. As a matter of fact, Easy365Manager eliminates the need to run an on-premises Exchange Server entirely, allowing you to remove it from your network.

Removing Exchange on-premises will save you both power, patching and policing. During 2021 more than one hundred thousand organizations were hacked by the Hafnium zero-day exploit that specifically targeted on-premises Exchange Server.