How to Create Dynamic Distribution Groups in Microsoft 365

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Dynamic Distribution Groups (DDGs) are available in both Microsoft Exchange Server and Exchange Online. They use recipient filters to automatically determine which recipients belong to the group.

DDGs are managed through the Exchange admin center and Exchange Online PowerShell. You can also use the Exchange admin center and Exchange Management Shell in on-premises Exchange Server, with additional options such as filtering recipients within a specific Active Directory OU.

Keep in mind that Dynamic Distribution Groups use recipient filters to determine their membership. Membership is calculated when a message is sent in Exchange Server Subscription Edition. The calculated membership list is stored by the service and refreshed periodically.

Starting in late May 2026, the time required to populate/recalculate an Exchange Online DDG depends on the number of recipients returned by its membership rules:

• 5,000 recipients or fewer: The membership list is populated immediately when a new DDG is created and recalculated immediately when its membership rules are modified. The DDG is available with the updated membership as soon as the operation completes.
• More than 5,000 recipients: Initial population or recalculation is performed by a background process and can take up to two hours. Exchange Online displays a warning in the Exchange admin center (EAC) and Exchange Online PowerShell when this delayed processing applies. During recalculation of an existing DDG, the previous membership list continues to be used until the new calculation is completed.
• Routine refresh: After initial population, Exchange Online refreshes the membership list at least once every 24 hours, regardless of group size.

Because of this calculated membership model, changes to recipient attributes aren’t necessarily reflected in DDG delivery immediately. A recipient can continue receiving messages, or fail to receive messages, until the membership list is refreshed or recalculated.

Creating a Dynamic Distribution Group in Exchange Server

For new Exchange Server SE deployments, Windows Server 2025 is a supported OS. Exchange Server SE also supports Windows Server 2022 and Windows Server 2019. We recommend Server Core as an installation option.

So, let’s look at how to create and manage DDGs and their recipient filters in Exchange Server. You can manage a dynamic distribution group with the Exchange Admin Center (EAC) web interface.

Let’s create a simple dynamic group that includes all users in the IT department. Follow the steps below:

1. Sign in to the Exchange Admin Center (EAC) for your on-premises Exchange Server.
2. Navigate to recipients > groups > click + and select Dynamic distribution group.
   

   

3. Specify the name of the new group and the Active Directory OU in which to create it.
   

   

4. Scroll down the group properties form. Here, you can choose which types of recipients will be included as members of the group: all, user/resource mailboxes, mail contacts, or mail-enabled groups.
5. In this case we have selected the Users with Exchange mailbox option.

   

6. Next, in the membership settings, define the rules that will automatically add users to the group.
7. Click Add a rule.
8. Recipient container, state, company, department and 15 custom attributes are available in the ECP web interface.
9. We selected Department (with the value IT) and specified the Recipient container (the Organizational Unit in AD from which users should be added to the dynamic group).
   

   

10. Click OK to create a new group.

All user mailboxes from the selected OU whose Department property is set to IT will be included in the dynamic distribution group we have created. Now, if a user is transferred to another department and the value of this attribute in AD changes, they will be automatically removed from this distribution list.

Checking the DDG filter in Exchange Server

How to check that the filter is working correctly and see which users are included in the DDG group? You cannot view the members of a dynamic group in ECP or in the Outlook address list.

Use PowerShell (Exchange Management Shell) to list the dynamic group members:

Get-Recipient -RecipientPreviewFilter (Get-DynamicDistributionGroup -Identity hq-admins).RecipientFilter| select Name, RecipientType, PrimarySmtpAddress

The command mentioned above previews the recipients that currently match the DDG’s recipient filter.

The current settings of the DDG filter can be viewed using the following command:

Get-DynamicDistributionGroup hq-admins| fl name,*filter*,*container

Note that in Exchange Server, DDG membership is evaluated when a message is sent to the group. Exchange Online uses a calculated membership model: the membership list is maintained by the service and refreshed periodically.

Important. In case you are using MemberOfGroup in a custom recipient filter, you need to specify the group’s Distinguished Name (DN)/canonical DN, not its display name. The group must be a distribution group or a mail-enabled security group that Exchange recognizes. Microsoft Entra security groups that aren’t mail-enabled can’t be used with MemberOfGroup. For example, you can retrieve the DN of a mail-enabled group with the command:

$dn = (Get-DistributionGroup "Marketing Department").DistinguishedName

Now you can use the DN in the recipient filter:

New-DynamicDistributionGroup `
-Name "Marketing Department Users" `
-RecipientFilter "((RecipientTypeDetails -eq 'UserMailbox') -and (MemberOfGroup -eq '$dn'))"

Creating a Dynamic Distribution Group with PowerShell

Creating and managing filters in DDG is much more flexible with PowerShell. For example, only about 20 user attributes that can be used as group filters are available in the ECP Web UI. You can check the complete list of filterable properties for RecipientFilter parameter in Exchange Server.

Let’s look at some typical PowerShell commands for creating and managing dynamic distribution groups in Exchange Server. Note that the following Exchange Management Shell commands work with Exchange Server Subscription Edition. You should use the Exchange Management Shell provided with your Exchange Server installation rather than a separate PowerShell module.

Creating a new dynamic group

Create a new dynamic group of all users whose Company field is TheITBros and whose City field is Houston:

New-DynamicDistributionGroup `
-Name "Houston TheITBros Team" `
-Alias "HOU-TheITBros" `
-RecipientContainer "theitbros.com/Houston/Groups" `
-RecipientFilter "((Company -eq 'TheITBros') -and (City -eq 'Houston'))"

After that, you need to verify that the new dynamic distribution group has been created successfully:

Get-DynamicDistributionGroup "Houston TheITBros Team"

In order to list all dynamic distribution groups, run the command:

Get-DynamicDistributionGroup |
Select-Object Name, PrimarySmtpAddress

Here is an example of a more advanced recipient filter:

New-DynamicDistributionGroup `
-Name "London IT Users" `
-Alias "LondonITUsers" `
-RecipientFilter "((RecipientTypeDetails -eq 'UserMailbox') -and (Department -eq 'IT') -and (Office -eq 'London'))"

Change the DDG settings with Set-DynamicDistributionGroup

You can use the Set-DynamicDistributionGroup cmdlet to change the DDG settings. In this example, we will exclude a specific user from the dynamic group by using a dedicated custom attribute. First, mark the user with the custom attribute:

Set-Mailbox -Identity "cyril.kardashevsky@theitbros.com" -CustomAttribute1 "ExcludeFromHoustonDDG"

Then you need to update the DDG recipient filter to exclude recipients with this attribute:

Set-DynamicDistributionGroup `
-Identity "Houston TheITBros Team" `
-RecipientFilter "((RecipientTypeDetails -eq 'UserMailbox') -and (Company -eq 'TheITBros') -and (City -eq 'Houston') -and (CustomAttribute1 -ne 'ExcludeFromHoustonDDG'))"

Note that you cannot change the membership rule of a dynamic distribution group created using PowerShell from the ECP web interface.

This dynamic distribution group was created by using the Exchange Management Shell. Use the Shell to change the filter.

In order to remove a dynamic distribution group, use the following command:

Remove-DynamicDistributionGroup "Houston TheITBros Team"

Creating a Dynamic Distribution Group in Exchange Online

Before running Exchange Online cmdlets, you need to connect to Exchange Online PowerShell with the command:

Connect-ExchangeOnline

Then you need to create a dynamic distribution group. Use the following command:

New-DynamicDistributionGroup `
-Name "Sales Team" `
-Alias "SalesTeam" `
-RecipientFilter "(Department -eq 'Sales')"

In order to view Dynamic Distribution Group members in Exchange Online, run the following command:

Get-DynamicDistributionGroupMember -Identity "Sales Team"

You can use Get-DynamicDistributionGroupMember in order to view the calculated membership of a dynamic distribution group in Exchange Online. The membership list is maintained by the Exchange Online service. For DDGs with 5,000 or fewer matching recipients, the membership list is populated/recalculated immediately when the group is created or its membership rules are modified. For larger DDGs, the initial population/recalculation can take up to two hours. After the initial population, the membership list is refreshed at least once every 24 hours.

If the calculated membership of an Exchange Online dynamic distribution group is not up to date, you can manually trigger a membership refresh with Set-DynamicDistributionGroup:

Set-DynamicDistributionGroup -Identity "Sales Team" -ForceMembershipRefresh

You can run a forced refresh only if more than one hour has passed since the previous membership refresh. This cmdlet is available for Exchange Online dynamic distribution groups.

The example mentioned above creates a dynamic distribution group that automatically includes all mailboxes where the Department attribute is set to Sales.

Wrapping up

Dynamic groups in Exchange Server are a powerful and convenient tool for managing distribution lists within an organization. Dynamic Distribution Groups (DDGs) are available in Exchange Server Subscription Edition (SE) and Exchange Online. They use recipient filters to automatically determine which recipients belong to the group.