There are many organizations maintaining multiple domains on a single Microsoft 365 or Azure AD tenant, in those cases there might be a need to create dynamic Microsoft 365 groups, security groups & distributions list based on the user’s domain to manage the group’s membership. On this blogpost, let us see how to

1. Create Dynamic Microsoft 365 group based on the user’s domain for Teams & Yammer
2. Create a Dynamic distribution list based on user’s domain in Exchange online

To begin with let us see some basics of a Dynamic group. The membership of a dynamic group will automatically update as people join, leave, or move within the organization whenever the user’s Azure Active Directory attributes are changed. In simple terms, rules determines the group membership. The users will be added or removed automatically as and when the user attributes change or users join and leave the tenant which reduces the administrative effort of adding and removing users from a group. Dynamic group can be created based on variety of attributes including role, location, department etc.

Create Dynamic Microsoft 365 group based on the user’s domain for Teams & Yammer

Microsoft Teams and Yammer (Microsoft 365 Connected) supports dynamic membership. It enables the membership of Team or Yammer to be defined by one or more rules that check for certain attributes in Azure AD. Microsoft Teams & Yammer creates a Microsoft 365 group in Azure AD. For this post, the membership rule will be simple one which is based on the user’s domain and country. You can also have a complex rule involving multiple Azure AD attributes like Title, Geography, Department etc. Before we proceed further, there are some pre-requisite & facts to be considered before creating a dynamic group.

• User Administrator or Global administrator role in Azure AD
• Users you foresee to be part of a dynamic group membership rule should have an Azure AD premium License P1 or P2
  • Microsoft 365 E3, E5, Front line workers MF3 & MF1 has Azure AD premium 1 service which should suffice.
• An Azure AD organization can have maximum of 5000 dynamic groups.
• Any number of Azure AD resources can be members of a single group.

Dynamic Membership based on Domain for Teams:

To create a Dynamic membership MS team, create a Microsoft 365 group first with Dynamic membership in Azure Active directory. You can create a dynamic group from PowerShell but here I will be using Azure Ad GUI to create the dynamic Microsoft 365 group with rule to add users based on their domain and country. I have added a domain m365pal.me to my Azure AD tenant which I will be using here for this example.

1. Sign in to Azure AD Admin center with administrator role in the Azure AD organization
2. Click Groups and then click + New Group
3. Select the Group type as Microsoft 365. Dynamic membership will also work with Security group but for team it should be Microsoft 365 group.
4. Enter the Group Name & Group email address
5. Select the Membership type as Dynamic User
6. Select the Owner and then
7. Under Dynamic user members section, click Add dynamic query
8. In Dynamic membership rules panel, add rule to define membership based on users domain & country
   • First rule for Domain: under Property column select userPrinicipalName, Operator should be Contains and the Value should be the domain name in format “@yourdomain.com”. This rule will add all users with the UPN user@yourdomain.com. Now click + Add expression to add the second rule
   • Second rule for country: under Property column select country, Operator should be  Equals and the value should be the country name.

9. You can also validate the rules by clicking the link Validate Rules and then by adding users to check if the user satisfies the rule
10. Click Save. This is how it should look like

11. Click Create.
12. After waiting for couple of minutes, check the group membership. Please find below screenshot for the group which has two members satisfying the condition. You can also notice the + Add members link is disabled since the group is dynamic membership and not assigned. To modify the rules, click the link Dynamic membership rules link.

13. Now we are ready to create the MS Teams, go to https://teams.microsoft.com/ and then click Join or create a team at the left bottom corner and then Click Create a team
14. Click From a group or team and then click Microsoft 365 group
15. Now select the group you have created in Azure AD and then click Create.

16. The team is now created, you can find the team on the list. Check the membership of the team which will have the two users satisfying the rules and the owner of the group. One more thing to notice here is the message which says The membership settings prevents you from adding or removing members.

17. Voila! Dynamic Microsoft team is now created & setup.

If you have an existing team to be converted to a Dynamic team, find the Microsoft 365 group in Azure AD for the Team you wish to convert and then update the membership status from Assigned to Dynamic user with membership rules

Dynamic Membership based on Domain for Yammer:

Yammer (Microsoft 365 Connected) also supports dynamic membership. Find the steps below to create a dynamic yammer group based on the user’s domain. Find the steps below

1. Sign in to https://yammer.com/ with your organizational ID
2. Click Create a Community and then Enter the name of the Community
3. Click the button Create

4. Now sign in to Azure AD Admin center to the update the membership settings of the Microsoft 365 group connected to the Yammer community. Find the yammer group and then click

5. Click Properties under the Manage blade and then change the membership type from Assigned to Dynamic user

6. After updating the membership type to Dynamic user. You will now have option to enter the dynamic query. Click dynamic query

7. In Dynamic membership rules panel, add rule to define membership based on users domain
   • Rule for Domain: under Property column select userPrinicipalName, Operator should be Contains and the Value should be the domain name in format “@yourdomain.com”. This rule will add all users with the UPN user@yourdomain.com. Now click + Add expression to add rules based on need
   • Click Save

8. Click Save. Wait for couple of minutes for the membership to be updated.
9. Now check the Yammer group in Yammer.com for the membership status. Please find below screenshot for your reference which will not have the + icon on the highlighted members section for adding users since this is now a dynamic yammer group

Also, Microsoft 365 group/Security group can be used for different use cases. See some sample use cases below

• You can use to target SharePoint page/news to specific audience with the help of Microsoft 365 group or Security group. Will it not be more powerful if you use dynamic groups within a SharePoint to target content certain group of audience!
• Assign Microsoft Licenses to users based on Dynamic Group.
• Grant access to an App (PowerApps etc) using the dynamic group targeting certain departments, geographies etc

Reference:

https://docs.microsoft.com/en-us/azure/active-directory/enterprise-users/groups-create-rule

https://docs.microsoft.com/en-us/azure/active-directory/enterprise-users/groups-dynamic-membership

https://docs.microsoft.com/en-us/microsoftteams/dynamic-memberships

https://docs.microsoft.com/en-us/yammer/manage-yammer-groups/create-a-dynamic-group

https://docs.microsoft.com/en-us/yammer/manage-yammer-groups/yammer-and-office-365-groups

https://docs.microsoft.com/en-us/azure/active-directory/enterprise-users/directory-service-limits-restrictions

Create a Dynamic distribution list based on user’s domain in Exchange online:

Dynamic distribution groups are mail-enabled Active Directory group to distribute email messages to all its members within a Microsoft Exchange organization. Unlike regular distribution lists that contain a defined set of members, the membership list for dynamic distribution groups is calculated each time a message is sent to the group, based on the filters and conditions that you define in the group. You can create a Dynamic Distribution list from Exchange Admin center as shown below but the options to write advanced filter conditions or rules are limited so PowerShell is preferred.

Dynamic Distribution list from PowerShell:

Make sure the Exchange online PowerShell module is installed. There are some limitations to create a recipient filter (Rules) that worked based on user’s domain with the operator like or contains but there is a workaround. The filter works based on the exchange property WindowsEmailAddress which is always the primary SMTP address, you can also consider using the property WindowsLiveID. Follow the steps below to create a Dynamic Distribution list based on user’s domain

1. Load the module by the running the command Import-Module ExchangeOnlineManagement
2. Connect to the Exchange online PowerShell in Microsoft 365

Connect-ExchangeOnline -UserPrincipalName userId@domain.com -ShowProgress $true

3. After authentication, enter the following command to create the Dynamic DL based on User’s domain. I have added the RecipientTypeDetails in the RecipientFilter to apply the filter rule only to user mailboxes which excludes the SharedMailboxes

New-DynamicDistributionGroup -Name "All Users - M365PAL DL" -RecipientFilter "(RecipientTypeDetails -eq 'UserMailbox') -and (WindowsEmailAddress -eq '*@yourdomain.com')"

4. You can also validate the users using the following script

Get-Recipient -RecipientPreviewFilter (Get-DynamicDistributionGroup "All Users - M365PAL DL").RecipientFilter

5. To view the attributes to be used in the recipient filter enter the following command

Get-User -Identity user@yourdomain.com | Format-List

Reference:

https://docs.microsoft.com/en-us/exchange/recipients/dynamic-distribution-groups/dynamic-distribution-groups

https://docs.microsoft.com/en-us/powershell/module/exchange/get-user

https://docs.microsoft.com/en-us/exchange/recipients/dynamic-distribution-groups/view-dynamic-distribution-group-members

Summary: On this post we have seen how to create dynamic groups based on user’s domain. Do some planning to start using the dynamic groups which will help reduce lot of administrative overhead. Hope you have found this informational & helpful. Let me know any feedback or comments on the comment section below