It is known that a single Microsoft Exchange account is not sending more than 10k emails per day.
It is also know that once activated – Microsoft 365 groups ownerless policy will be sending notifications for all groups in scope to specified number of group members within 24 hours.
The question is: what if there are more than 10,000 notifications to send (e.g. 4,000 ownerless groups and the policy is configured to send notification to 3 members per group – that gives us 12,000 notifications to send)? Would the policy send 10k notifications and the rest 2k notifications the next day?
I’m conducting an experiment. I created 10k groups in my lab tenant with one owner and 3 random members. Then I configured a policy that is sending notification to a 3 most active members (in this case – random members). And then I made all these groups ownerless by deleting the single owner Id from Azure AD (Microsoft Entra).
Here is what I got from users perspective:
user
user groups number
got messages day 1
got messages day 2
got messages total
1 Roger
5012
1374
2 Dick
5039
1349
3 Bob
5108
3412
4 Bapu
4908
1376
5 Stas
4996
1437
6 David
4959
1377
total
10325
Here is what audit log says:
Events “OwnerlessGroupNotified” day 1: 4949 Events “OwnerlessGroupNotified” day 2: 95 Events “OwnerlessGroupNotified” total: 5044 Each event details says 3 members were notified.
It seems like groups are selected by policy in random order.
Massive E-mails sending was started 43 minutes after midnight UTC
“OwnerlessGroupNotified” were logged at the rate of 1925 events during 1-st hour, 2029 events during 2-nd hour, 785 events during 3-rd hour, 176 events during 4-th hour, 26 events during 5-24 th hour, 95 events during next 25-48 hours so max rate was one event every 3 seconds in the beginning (or 1 e-mail per second) …
You are trying to register an application at SharePoint site with appregnew.aspx page and you are getting an error or notification message “Your SharePoint tenant admin doesn’t allow site collection admins to create an Azure Access Control (ACS) principal“.
Or you are trying to provide ACS-based permissions for an application to SharePoint site with appinv.aspx page and you are getting “Your SharePoint tenant admin doesn’t allow site collection admins to update app permissions. Please contact your SharePoint administrator.”
You can still view and even delete your apps permissions from /_layouts/15/appprincipals.aspx page:
Reason
This is due to a recent update to Microsoft 365 (tenant governance security measures enhancement MC660075) implemented by Microsoft in Aug/Sep 2023. According to the update, only tenant administrators can create or update ACS service principal by default.
The root cause for this is that the Microsoft is pushing developers out of that legacy ACS-based SharePoint Apps-only service principals towards Azure-registered applications with Sites.Selected API permissions as they are more secure etc. In Nov 2023 Microsoft announcement retirement of ACS principals.
Key differences between ASC and Sites.Selected are:
ACS-based SharePoint app/permissions
Apps registered in Azure with Sites.Selected API permissions
Support authentication with client secret only, Secrets are valid for 1 year exactly.
Support authentication with client secret and/or certificate, custom expiration time.
Support granular access to SharePoint site, e.g. to site collection or web (subsite) or a specific list or library.
Support only access to entire site collection (but Microsoft says granular access is coming) Granular permissions are available – ‘Lists.SelectedOperations.Selected’, ‘ListItems.SelectedOperations.Selected’ and ‘Files.SelectedOperations.Selected’ permissions allows to provide application access to list, library or list item or particular documents
Support only classic SharePoint REST API and CSOM
Support both – classic SharePoint REST API and CSOM and Microsoft Graph API
App id (client id) is created via appregnew.aspx at a specific SharePoint site by site collection administrator (disabled in Sep 2023).
App id (client id) is created in Azure portal (Entra Id), API Sites.Selected permissions are configured via Azure portal (Entra Id) and require tenant admin consent.
Permissions for the app to a site are provided at the site by site collection administrator via appinv.aspx page (disabled in Sep 2023).
Permissions for the App to to a specific SharePoint site are provided via Graph API by SharePoint admin with PowerShell script.
Solution #1 – switch to Sites.Selected
Register an application in Azure (via Entra Id – Azure portal GUI, PowerShell script or your company’s specific helpdesk/servicedesk request)
Update the app so both – MS Graph API Sites.Selected and SharePoint Sites.Selected permissions are configured, then
API permissions must be consented – so you’d seek/request your tenant admin consent
Obtain and upload client certificate (recommended) or generate client secret (at this moment you should be able to authenticate to tenant)
Request access for the app to a specific SharePoint site – your SharePoint service admin should be able to do that (at this moment you should be able to authorize to your SharePoint site).
Validate your app has access to the target SharePoint site with PowerShell (check validation scripts below under References).
Use recommended by Microsoft technique, code samples are available for the most popular languages/platforms – Python, C#, Java etc. (check below under References).
Secure your certificate and/or secret. It is not a good idea to use hard-coded secrets, so consider using special services/storages for secrets (aka Vaults)
If you are hosting your application in Azure – consider using managed identity.
There are 3-rd party (and Microsoft) apps developed using classic approach (examples – Azure data Factory, Alteryx). So in some cases Sites.Selected permissions are not enough to get access to SharePoint.
Solution #2 – admin to register/update an ACS app
This option is acceptable if you have existing application that require ACS-based access. This option is not recommended for new development, as ACS is deprecated and scheduled for retirement.
Microsoft (MC660075 in Message Center): “site collection admin will be unable to register app or update app permissions through above pages unless authorized explicitly by the SharePoint tenant admin” and “With this update site owners will not be able to register/update apps unless the tenant admin explicitly allows it.”
That is incorrect. Site collection admin cannot register app (appregnew) or provide permissions to the app (appinv) anymore. Tenant admin does not authorize site collection admins. Instead tenant (or SharePoint) admin can register an app or provide permissions to the app at a specific site (not changing the entire default behavior back…). But there was no such option (!) in the middle of October 2023, when this feature was enabled at all tenants. Even having a SharePoint admin or tenant admin permissions – if you tried to register an app with AppRegNew.aspx – you got the same error message “Your SharePoint tenant admin doesn’t allow site collection admins to…”.
Later (Checked today – Nov 6, 2023) it seems like Microsoft has implemented it! E.g. now SharePoint or tenant admin is able to register an app with AppRegNew.aspx or update it with AppInv.aspx at any specific site collection. SharePoint or tenant admin must also be among this site collection admins.
It is ok (and I’d say the preferred way) to provide ACS permissions to the app registered in Azure, so do not register apps in SharePoint anymore (do not use AppRegNew.aspx).
Bottom line: if ACS-based permissions are required for app here you go:
register application in Azure (Entra id)
activate your SharePoint service/tenant admin role
ensure you are also target site collection administrator
navigate to the site appinv.aspx page – e.g. “https://yourtenant.sharepoint.com/sites/yoursite/_layouts/15/appinv.aspx” and us Azure registered app (client) Id. E.g. for lookup provide
Azure registered app (client) Id for – click lookup
localhost as app domain
https://localhost as redirect url
Permission Request XML – depending on permissions you need, e.g. for full app access to entire site collection:
It is possible to switch back this new default behavior that prevents site collection admin to register/update apps at SharePoint. This is done with PowerShell command
To run this command – you’d need to be a SharePoint service or tenant admin.
But this will be a step back on your journey in improving m365 tenant safety, as after that you’ll have a self-registered service principals out of control again. So devs will be using it not being aware of ACS retirement and when Microsoft switch off ACS – it will be a disaster, as all app will stop working. That is why Microsoft implemented this feature to soft-disable ACS and allowed us 2 years to redesign or apps and migrate from ACS to Entra Id apps with Sites.Selected. So this solution is not recommended.
In case you really need an exception to provide an ACS-based service principal – there is Solution number 2.
Full text of Microsoft’s MC660075 message
(Updated) SharePoint admin control for App registration / update
Tag MAJOR UPDATE ADMIN IMPACT FEATURE UPDATE
Message Summary Updated August 30, 2023: We have updated the content below for clarity. Thank you for your patience.
This is an enhancement to the security measures for administrative governance that modifies the default procedures for SharePoint app registration via AppRegNew.aspx page and permission updates via AppInv.aspx page. Following the implementation of this change, site collection admin will be unable to register app or update app permissions through above pages unless authorized explicitly by the SharePoint tenant admin.
Upon attempting to register an application on AppRegnew.aspx page, a notification will be displayed stating “Your SharePoint tenant admin doesn’t allow site collection admins to create an Azure Access Control (ACS) principal. Please contact your SharePoint tenant administrator.”
Similarly, upon attempting to update app permissions on AppInv.aspx page, a notification will be displayed stating “Your SharePoint tenant admin doesn’t allow site collection admins to update app permissions. Please contact your SharePoint tenant administrator.”
Kindly note that app registration and permission update via Microsoft Azure portal are not impacted by this change.
When this will happen:
The rollout process is scheduled to commence in late August and is expected to conclude in mid-September.
How this will affect your organization:
With this update site owners will not be able to register/update apps unless the tenant admin explicitly allows it.
To modify the default behavior, the tenant administrator must execute the following shell command to explicitly establish the flag as TRUE, thereby superseding the default value of FALSE. The service principal can only be created or updated by the tenant administrator by default. However, when the flag is set to TRUE, both the SharePoint tenant admin and site collection admin will be able to create or update the service principal through SharePoint.
The shell command is: Set-SPOTenant -SiteOwnerManageLegacyServicePrincipalEnabled $true
Note: The property ‘SiteOwnerManageLegacyServicePrincipalEnabled’ becomes visible in tenant settings after SharePoint Online Management shell is updated to 16.0.23710.12000 or a later version. But before this rollout, the value will always be TRUE even explicitly set to FALSE. It will only automatically be switched to FALSE as the default value after the rollout is launched.
What you need to do to prepare:
No proactive measures are required to prepare for this change. Nevertheless, it is advisable to inform your users of this modification and update any relevant documentation as necessary.
That’s a very common problem in SharePoint world. You are looking for a site owner but there is no tool available for regular user to find who owns the site.
Scenarios.
You get a link to some SharePoint site, but you do not have access to it. You requested access but nobody has responded. You need to find who is the site owner.
After many years working with SharePoint I wrote a lot of PowerShell scripts that help me support, troubleshoot, administer and secure SharePoint. So I’m sharing my scripts with you.
You are seeing messages “This form can’t be distributed as it is asking for personal or sensitive information. Contact your admin for assistance. Terms of use”
or
“Form can no longer be accessed. This form has been flagged for potential phishing. Technical details”
Cause
The reason is: Microsoft enabled automated machine reviews to proactively detect the malicious collection of sensitive data in forms and temporary block those forms from collecting responses. More about it.
Solution
Ask your tenant global or security admin to go to the Microsoft Security Administration (Defender) Alerts:
If your list of alerts is too big – use filter by Policy: “Form blocked due to potential phishing attempt”.
To unblock the form or confirm it is phishing – admin should open the alert:
And then click “Review this form“. “Review the form” opens the page “https://forms.office.com/Pages/AdminPhishingReviewPage.aspx?id=” where is the form Id.
Then global/security admin can review the form and unblock it or confirm it is phishing:
Microsoft recently implemented “Adaptive” retention policies. At step 2 of “Create retention policy” you’ll be asked “Choose the type of retention policy to create”: “A policy can be adaptive or static. Advantage of an adaptive policy will automatically update where it’s applied based on attributes or properties you’ll define. A static policy is applied to content in a fixed set of locations and must be manually updated if those locations change.”
And if you selected “Adaptive” – on the next step you will need to provide the adaptive scope (so at this moment you should already have created your adaptive scopes):
So, let us create your adaptive scopes. What type of scope do you want to create? SharePoint sites…
And then you’ll have nothing more then set of conditions:
where you can use objects: “Site Url”, “Site Name” and “Refinable String 0″..”Refinable String 99”. Conditions would be “is equal to”, “is not equal to”, “starts with” and “not starts with”. Or you can select “Advanced query builder” and enter KQL query.
Advanced query builder for SharePoint Adaptive Scope
I will be saving my personal gotchas on Microsoft 365 External Access and Guest Access in SharePoint and Teams
We configure external/guest access in AAD, m365 Admin Center, Teams Admin Center, SharePoint Admin Center, specific Group, Team or SharePoint site.
We can configure external guest access directly, or can configure sensitivity labels and policies in Purview (Compliance Admin Center). Configuring sensitivity labels for sites/groups we configure external guest access settings. Configuring sensitivity labels policies we apply labels.
External access via “All Users” group
Be careful with “All users” group created as part of the process. Microsoft: “The dedicated All Users group includes all users in the directory, including guests and external users.” And indeed, “All Users” group by default include external users.
So here is the scenario: we have a site where external sharing is enabled, and someone is sharing a specific file1 or folder1 with some external users. The other site/group member is sharing another file2/folder2 with “All Users” assuming All Users means all this group member. This gives external users access to file2/folder2.
Remediation
Option 0: remove “All Users” group
Option 1: exclude External users or Guest users from “All Users” group:
(user.userPrincipalName -notContains "#EXT#@")
or
(user.userType -ne "Guest")
Option 2: schedule a job that removes “All Users” from all sites UIL. Optionally inform site owners not to use “All Users” but use “Everyone except external users”.
Note: When you follow instructions provided by Microsoft, beware that “Connect-AzureAD” works only in Windows .net framework – i.e. PowerShell 5.1. if you try to run it in PowerShell 7 – you can get “Connect-AzureAD: One or more errors occurred. (Could not load type ‘System.Security.Cryptography.SHA256Cng’ from assembly ‘System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089’.)” Error. (check Connect-AzureAD Could not load type ‘System.Security.Cryptography.SHA256Cng’ from assembly)
Configuring Sensitivity Labels
Sensitivity labels are configured under Microsoft Purview (Compliance Center), Solutions, Information Protection. You’d need a global admin or “Compliance Administrator” or “Azure Information Protection Administrator” (?) role:
Since we are talking sensitivity labels for SharePoint Sites (not documents), we define label scope as “Groups and Sites”: “Configure privacy, access control, and other settings to protect labeled Teams, Microsoft 365 Groups, and SharePoint sites.”
Then we define which protection settings for groups and sites we should configure on the next steps: – Privacy and external user access settings – Control the level of access that internal and external users will have to labeled teams and Microsoft 365 Groups. – External sharing and conditional access settings – Control external sharing and configure Conditional Access settings to protect labeled SharePoint sites.
If we selected previously “Privacy and external user access settings” – now we need to select group/team privacy (These options apply to all Microsoft 365 Groups and teams, but not standalone sites). When applied, these settings will replace any existing privacy settings for the team or group. If the label is removed, users can change privacy settings again. You can also allow external user access – if group owner will be able to add guests:
Next step – define external sharing and conditional access settings. Specifically, if the content of the SharePoint site can be shared with Anyone (anonymously) or with authenticated users (new or existing) or no external sharing is allowed:
And you can either control the level of access users have from unmanaged devices or select an existing authentication context to enforce restrictions:
Configuring sensitivity labels policies
Sensitivity label policy is basically which label should be available to apply for what users and some other settings like – do users need to provide justification before removing a label or replacing it with one that has a lower-order number or – will users be required to apply labels and optionall the default label
View existing sensitivity labels
“Global reader” role allows view existing sensitivity labels configuration:
Wording would be a little different, but all aspects of the label configuration will be mentioned. E.g. when editing GUI says label scope is “Groups & sites”, read-only label summary defines Scope as “Site, UnifiedGroup”.
Gotchas
Site sensitivity label is applied to site collection only and cannot be applied to subsite (web object).
Applying sensitivity labels programmatically
To apply a label to a m365 group or Teams site with a group behind: MS Graph API support only Delegated permissions.
“Set-PnPSiteSensitivityLabel” works in the current site context. Description says “If the site does not have a Microsoft 365 Group behind it, it will set the label on the SharePoint Online site and will not require Microsoft Graph permissions and will work with both delegate as well as app only logins.” In fact (7/22/2022) app permissions are not working. This cmdlet can assign label to a standalone or a group-based site only with delegated permissions.
“Set-PnPTenantSite” allows you to remove or apply site sensitivity label to both standalone and group-based sites with app permissions. Furthermore, group and team settings respect this. I.e. if you apply label to a group-based site – group will pick this up.
Channel sites should inherit sensitivity label from root site. I’m not sure if it’s a bug but – when you create a team and select sensitivity label as part of team creation process – all the channel sites you create after (Private or Shared) will inherit sensitivity label immediately – when you apply sensitivity label to an existing team – with existing channel sites – in this case Private channel sites inherit team sensitivity label immediately, but with Shared channel sites it’s strange: GUI shows sensitivity label assigned, but site object model does not.
