A Complete Guide to Creating User Mailboxes in Exchange Admin Center
You can create mailboxes in Exchange Admin Center by following easy steps. To create mailboxes securely, you must have the right permissions to keep your group safe. If you miss a step or set up permissions wrong, someone might get in who should not. You could also lose data. Problems like random permission changes or phishing attacks can happen if you miss important settings. Always check your permissions and turn on audit logs to find strange activity. When you get ready to create mailboxes, you keep things simple and safe.
Key Takeaways
Always make sure you have the right permissions before you create mailboxes. This helps keep your system safe.
Use the Exchange Admin Center or Microsoft 365 Admin Center to make mailboxes for new or current users. Follow the right steps each time.
Give users the correct licenses so their mailboxes work, especially in Exchange Online.
Turn on mailbox and admin audit logging to watch what happens and stop people who should not get in.
Use PowerShell if you need to make mailboxes faster or do special jobs for many users.
Prerequisites
Permissions Needed
You need the right permissions before you begin. You cannot make user mailboxes in the new Exchange Admin Center right away. First, you must make a user account and give it an Exchange Online license. Most people do this in the Microsoft 365 admin center or by using Exchange Online PowerShell. You need recipient provisioning permissions for this job. These permissions help you manage mailboxes and user accounts. If you do not know your permissions, look in the 'Recipients' part of the Exchange Online feature permissions guide. Always check your access before you start. This keeps your group safe and helps you avoid mistakes.
User Account Types
You can make mailboxes for different users. Exchange Admin Center lets you make a new Active Directory user account and mailbox at once. You can also turn on a mailbox for a user who does not have one yet. Sometimes, you may need to set up a linked mailbox for users in another trusted AD forest. Here is a table that shows the mailbox types you might use:
Pick the type that fits what you need.
Security Considerations
Security is important when you make mailboxes. You want to keep your users and data safe. Here are some ways to help you stay secure:
Use role-based access control. Only give permissions to people who need them.
Turn on mailbox audit logging. This shows who does what in each mailbox.
Set up admin audit logging. This lets you see when permissions change.
Check admin access often. Make sure only the right people have it.
Watch for odd things, like too many logins or big data moves.
Use safe connections, like TLS, to protect data as it moves.
Keep your Exchange servers updated to stop new threats.
Tip: Always tell your IT team that their actions are tracked. This helps everyone follow the rules and keeps your group safe.
Create Mailboxes in Exchange Admin Center
Accessing the Admin Center
You must open the Exchange Admin Center to make mailboxes. First, check if your account has the right permissions. If you are an admin, you should be in the "Organization Management" group. Open a web browser like Microsoft Edge or Chrome. Type the Exchange Admin Center web address like this:https://<exchangeservername>/ecp
For example, you might use https://exchangeserver.domain.local/ecp. Enter your username and password when asked. If it is your first time, you will choose your language and time zone. After you log in, you will see the dashboard. Here, you can manage mailboxes and other settings.
If you use Exchange Online, go to
https://admin.exchange.microsoft.com
. Sign in with your Microsoft 365 admin account. Use the menu on the left to find "Recipients" and then "Mailboxes." Now you are ready to make mailboxes for users.
Tip: Always type the full server name in the web address. This helps you avoid problems when logging in.
New User Mailbox
You can make mailboxes for new users in the Exchange Admin Center. Here are the steps you need to follow:
In the Exchange Admin Center, go to Recipients and pick Mailboxes.
Click the + icon and pick User mailbox.
On the "New user mailbox" page, pick New user.
Fill in the needed information:
Alias
First name
Initials (if needed)
Last name
Display name
Name
Organizational Unit
User login name
Set a password and confirm it. Make sure the password follows your company’s rules.
You can check a box to make the user change their password the first time they log in.
Click Save to make the new user and their mailbox.
If you want, click More options to pick a mailbox database, set up an archive mailbox, or assign an address book policy.
Click Save again to finish.
Now you have made a new user and mailbox at the same time. This is useful when you add someone new to your team.
Note: In Exchange Online, you usually make mailboxes by creating a user in the Microsoft 365 admin center and giving them a license. The steps above work best for on-premises Exchange.
Existing User Mailbox
Sometimes, users already have accounts but do not have mailboxes. Here is how you give them a mailbox:
Log in to the Exchange Admin Center and go to Recipients > Mailboxes.
Click the + icon and pick User Mailbox.
Choose Existing User.
Click Browse and pick the user from the list.
If you want, click More Options to pick a mailbox database, set up an archive mailbox, or assign an address book policy.
Click Save to turn on the mailbox for the user.
In Exchange Online, you cannot make mailboxes directly for existing users in the Exchange Admin Center. Instead, you give the user an Exchange Online license. The mailbox is made automatically when the license is active.
Tip: If you need to make mailboxes for many users at once, you can use PowerShell to do it faster.
Assigning Licenses
Licenses are needed when you make mailboxes, especially in Exchange Online. Without a license, the mailbox will not work. Here is what you should know:
User mailboxes in Exchange Online are made by giving Microsoft 365 licenses that include Exchange Online service plans.
Common licenses are Office 365 E1, E3, and E5. These plans give users email and other Microsoft 365 services.
To give a license, go to the Microsoft 365 admin center, find the user, and add the right license. You can pick only Exchange Online if you do not want to give other apps.
If you do not give a license, the mailbox will stop working after 30 days.
Shared mailboxes do not need a license unless they are bigger than 50GB or use special features.
Note: Always check that you have enough licenses before you make mailboxes for new users.
Differences Between Exchange Online and On-Premises
There are some differences when you make mailboxes in Exchange Online and on-premises Exchange:
In Exchange Online, mailbox creation is linked to licensing. You make mailboxes by giving licenses in the Microsoft 365 admin center.
In on-premises Exchange, you make mailboxes right in the Exchange Admin Center or with PowerShell. You manage mailbox types and settings yourself.
In hybrid setups, you must make mailboxes on the on-premises server. Use commands like
New-RemoteMailboxand set theRemoteRoutingAddress. These mailboxes sync to Exchange Online.Changes to mailbox types in hybrid setups must be done on-premises to keep everything working together.
Tip: Always follow your company’s steps for making mailboxes, especially if you use a hybrid setup.
Now you know how to make mailboxes for both new and existing users in Exchange Admin Center. You also know how licensing works and what makes Exchange Online different from on-premises Exchange. With these steps, you can help your group work well.
Troubleshooting
Permission Issues
You may have permission problems when making a mailbox. These problems can stop you from finishing your work. Here are ways to check and fix common permission problems:
Check that no “deny” permission is set for the ms-Exch-EPI-Token-Serialization user right on your Exchange server. This is needed if you use Exchange Server 2013 or 2016.
After making a mailbox, see if the user can set up their Outlook client. This helps you know if the mailbox works.
Double-check the OWA (Outlook Web App) URL you use to log in. Make sure the DNS entries for the hostname are right.
Try other OWA URLs, like
http://servername/owa, to see if you can log in.Log in to OWA right on the Exchange server. This helps you find out if the problem is with your network or the server.
Tip: Always give users only the permissions they need. Check mailbox permissions often to see if anything changed without you knowing.
User Not Found
Sometimes, you might see a “User Not Found” error. This can happen for a few reasons:
If you just made a new user in Active Directory, it might not show up right away in Exchange Admin Center. This happens because AD and Exchange need time to sync.
Problems with AD replication, like broken domain controllers, can cause this error.
Use commands like
repadmin /showreplandrepadmin /replsumto check AD replication status.Make sure new users are copied to all domain controllers.
If your domain controllers are in different places, force AD replication after you make new users.
Fix any AD replication problems, then check if the error is gone.
If your admin account is not in the “Organization Management” group, you might not see users. Add your account to this group in Active Directory to fix this.
Creation Errors
Mailbox creation can fail for many reasons. Here is a table with some common errors, what causes them, and how you can fix them:
If you see “Cannot open mailbox /o=First Organization /ou=Exchange Administrative Group,” check if the mailbox database is mounted and all Exchange services are running. Sometimes, restarting the server helps, but try not to cause downtime if you can.
Other Methods
Sometimes, you need more than the Exchange Admin Center. You may want to work faster or help many users at once. You might also want special reports. Two popular ways to do this are PowerShell and the Microsoft 365 Admin Center.
PowerShell
PowerShell helps you do tasks automatically. It is good for making mailboxes for many users. You can also use it to get reports that the admin centers do not have. PowerShell is helpful for hard jobs, like checking mailbox status and licenses together.
Before you start, check your setup:
Use an Exchange Online service account. This account must be in Azure Active Directory. It needs the Exchange administrator or global administrator role.
If you use more than one access node, your account needs local logon rights.
For public folders, you need owner permissions at all folder levels.
You do not need a license for the service account if you change it to a shared mailbox.
Set up a remote PowerShell session to Office 365.
Assign permissions, like view-only recipient, using PowerShell commands.
Here is a simple example to make a mailbox for a user:
# Connect to Exchange Online
$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session
# Enable mailbox for user
Enable-RemoteMailbox -Identity "username@domain.com" -PrimarySmtpAddress "username@domain.com"
💡 PowerShell is good for automating, bulk tasks, or special settings. It saves time and gives you more control.
Microsoft 365 Admin Center
The Microsoft 365 Admin Center is easy to use. It is good if you like web pages. You can use it for one user or many users at once.
To make mailboxes here, follow these steps:
Go to the Microsoft 365 admin center. Open the Active users tab.
Click Add a user.
Fill in the user's display name, username, and password.
Pick the user's location.
Give a product license that has Exchange Online. This will make the mailbox.
Finish any extra profile details.
For many users, use Add multiple users and upload a CSV file. Give licenses during or after the import.
📝 The Microsoft 365 Admin Center is best for simple mailbox creation and small teams. For big jobs or special reports, PowerShell is better.
Pick the way that works for you. If you need to make mailboxes for many users or want special reports, use PowerShell. If you want a simple process, use the Microsoft 365 Admin Center.
Best Practices
Naming Conventions
When you make user mailboxes, use clear naming rules. This helps everyone stay organized. If all mailboxes have the same style, you can find them faster. Here are some easy tips you can use:
Use both letters and numbers in mailbox names. This makes it easier to sort and search.
Group mailboxes by last name, like “A to E” or “F to K.” This helps you find people quickly.
Add details like the server name if you have many servers.
Do not use names that are too hard or confusing. Pick names that show what the mailbox is for.
Keep your naming rules simple. Think about how your team might grow in the future.
Make sure your naming style follows the law and helps you recover mailboxes if needed.
Tip: In Exchange Online, each mailbox “Name” property now uses a special ID. For daily work, use DisplayName or alias to find and manage mailboxes. If you use scripts, change them to look for DisplayName or alias instead of “Name.”
Ongoing Management
After you make mailboxes, you need to keep them working well. You do this in Exchange Admin Center under Recipients > Mailboxes. Here, you can change settings for each user. You might update email addresses, set mailbox limits, or give permissions.
Here are some things you should check often:
Set up groups for teams.
Change mail flow rules to control messages.
Manage resource mailboxes for rooms or equipment.
Add or change SMTP addresses.
Give “Send on Behalf” or “Full Access” permissions.
Block unwanted senders to stop spam.
Turn on archive mailboxes for more storage.
You will see different tabs in mailbox settings, like General, Organization, Delegation, and Mailbox. Each tab lets you change things like user info, permissions, message limits, and more.
Check these tasks often to keep mailboxes safe, organized, and ready for your team.
You have learned how to make mailboxes in Exchange Admin Center. Here is a short summary of what to do:
1. Log in to the Microsoft Entra admin center with the right permissions.
2. Click on Users, then pick All users.
3. Click New user and type in the needed details.
4. Check your work and finish making the user.
Always look at your permissions before you begin. Use smart steps like blocking auto-forwarding and turning on security rules. Set up mailbox auditing to watch for problems. If you have trouble, try the troubleshooting ideas. You can also use PowerShell or the Microsoft 365 Admin Center if you want more ways to do things. Check your mailbox settings often to keep things safe and working well.
FAQ
How do you check if a mailbox was created successfully?
You can open the Exchange Admin Center and go to Recipients > Mailboxes. Look for the user’s name in the list. If you see it, the mailbox is ready.
Can you delete a mailbox without deleting the user account?
Yes, you can. In the Exchange Admin Center, select the mailbox and choose Disable. This removes the mailbox but keeps the user account active.
What happens if you assign the wrong license?
If you give the wrong license, the mailbox might not work as expected. You can fix this by removing the wrong license and adding the correct one in the Microsoft 365 admin center.
How long does it take for a new mailbox to appear?
Usually, new mailboxes show up in a few minutes. Sometimes, it can take up to an hour. If you do not see it, try refreshing the page or signing out and back in.