Moving Office 365 Mailboxes to IMAP Servers - What’s the Best Approach
I’ve recently been looking into scenarios where organizations need to move mailboxes from Microsoft 365 to IMAP based email servers, and I noticed this is still a common requirement in many migrations. In most cases, the challenge is not just moving emails, but making sure everything like folder structure, old emails, and user data stays intact without creating too much disruption for users. From what I’ve seen, doing this manually can get very complex, especially when there are multiple mailboxes or large data volumes involved. That’s where migration tools usually come into the picture. Most tools simplify things by handling: 1. Secure connection to Microsoft 365 accounts 2. Bulk mailbox migration 3. Preserving folder hierarchy 4. Reducing downtime during the move 5. Avoiding duplicate data issues One thing I’ve noticed is that running a small pilot migration first always helps. It gives a clear idea of how the actual migration will behave before moving all users. Has anyone here worked on Office 365 to IMAP migration at scale? Would be good to know what approaches or tools worked best in your case and what challenges you faced during the process.Using Graph Delta Queries with Entra ID Groups
Delta queries are a Microsoft Graph mechanism to allow applications to query resources to find objects that have changed since a baseline was established. The technique is most useful for applications that need to synchronize a local store with online content. It’s not an appropriate method to use for reporting changes to Entra ID groups because knowing that an object changed doesn’t mean much by itself. https://office365itpros.com/2026/06/25/graph-delta-queries-entra-id-groups/Entra ID Tightens Conditional Access Processing for Baseline Scopes
Microsoft is closing a gap in conditional access policies where apps that only request baseline scopes with at least one exclusion are not processed. The rollout has already started and should be finished by mid-August. For most tenants, the change shouldn’t be an issue, but it is possible that some apps are in use that fit the profile and cannot handle conditional access. If MC1223829 appeared in your tenant, it’s time to check. https://office365itpros.com/2026/06/19/baseline-scopes-ca/I built a free, open-source M365 security assessment tool - looking for feedback
I work as an IT consultant, and a good chunk of my time is spent assessing Microsoft 365 environments for small and mid-sized businesses. Every engagement started the same way: connect to five different PowerShell modules, run dozens of commands across Entra ID, Exchange Online, Defender, SharePoint, and Teams, manually compare each setting against CIS benchmarks, then spend hours assembling everything into a report the client could actually read. The tools that automate this either cost thousands per year, require standing up Azure infrastructure just to run, or only cover one service area. I wanted something simpler: one command that connects, assesses, and produces a client-ready deliverable. So I built it. What M365 Assess does https://github.com/Daren9m/M365-Assess is a PowerShell-based security assessment tool that runs against a Microsoft 365 tenant and produces a comprehensive set of reports. Here is what you get from a single run: 57 automated security checks aligned to the CIS Microsoft 365 Foundations Benchmark v6.0.1, covering Entra ID, Exchange Online, Defender for Office 365, SharePoint Online, and Teams 12 compliance frameworks mapped simultaneously -- every finding is cross-referenced against NIST 800-53, NIST CSF 2.0, ISO 27001:2022, SOC 2, HIPAA, PCI DSS v4.0.1, CMMC 2.0, CISA SCuBA, and DISA STIG (plus CIS profiles for E3 L1/L2 and E5 L1/L2) 20+ CSV exports covering users, mailboxes, MFA status, admin roles, conditional access policies, mail flow rules, device compliance, and more A self-contained HTML report with an executive summary, severity badges, sortable tables, and a compliance overview dashboard -- no external dependencies, fully base64-encoded, just open it in any browser or email it directly The entire assessment is read-only. It never modifies tenant settings. Only Get-* cmdlets are used. A few things I'm proud of Real-time progress in the console. As the assessment runs, you see each check complete with live status indicators and timing. No staring at a blank terminal wondering if it hung. The HTML report is a single file. Logos, backgrounds, fonts -- everything is embedded. You can email the report as an attachment and it renders perfectly. It supports dark mode (auto-detects system preference), and all tables are sortable by clicking column headers. Compliance framework mapping. This was the feature that took the most work. The compliance overview shows coverage percentages across all 12 frameworks, with drill-down to individual controls. Each finding links back to its CIS control ID and maps to every applicable framework control. Pass/Fail detail tables. Each security check shows the CIS control reference, what was checked, what the expected value is, what the actual value is, and a clear Pass/Fail/Warning status. Findings include remediation descriptions to help prioritize fixes. Quick start If you want to try it out, it takes about 5 minutes to get running: # Install prerequisites (if you don't have them already) Install-Module Microsoft.Graph, ExchangeOnlineManagement -Scope CurrentUser Clone and run git clone https://github.com/Daren9m/M365-Assess.git cd M365-Assess .\Invoke-M365Assessment.ps1 The interactive wizard walks you through selecting assessment sections, entering your tenant ID, and choosing an authentication method (interactive browser login, certificate-based, or pre-existing connections). Results land in a timestamped folder with all CSVs and the HTML report. Requires PowerShell 7.x and runs on Windows (macOS and Linux are experimental -- I would love help testing those platforms). Cloud support M365 Assess works with: Commercial (global) tenants GCC, GCC High, and DoD environments If you work in government cloud, the tool handles the different endpoint URIs automatically. What is next This is actively maintained and I have a roadmap of improvements: More automated checks -- 140 CIS v6.0.1 controls are tracked in the registry, with 57 automated today. Expanding coverage is the top priority. Remediation commands -- PowerShell snippets and portal steps for each finding, so you can fix issues directly from the report. XLSX compliance matrix -- A spreadsheet export for audit teams who need to work in Excel. Standalone report regeneration -- Re-run the report from existing CSV data without re-assessing the tenant. I would love your feedback I have been building this for my own consulting work, but I think it could be useful to the broader community. If you try it, I would genuinely appreciate hearing: What checks should I prioritize next? Which security controls matter most in your environment? What compliance frameworks are most requested by your clients or auditors? How does the report land with non-technical stakeholders? Is the executive summary useful, or does it need work? macOS/Linux users -- does it run? What breaks? I have tested it on macOS, but not extensively. Bug reports, feature requests, and contributions are all welcome on GitHub. Repository: https://github.com/Daren9m/M365-Assess License: MIT (free for commercial and personal use) Runtime: PowerShell 7.x Thanks for reading. Happy to answer any questions in the comments.Microsoft Tightens Security for Self-Service Password Reset
Microsoft plans to improve the security of the Self-Service Password Reset (SSPR) facility in September 2026 by requiring users to register at least one authentication method. SSPR will then use the registered authentication method to verify user accounts when changing passwords. The change aligns SSPR with user sign-ins and improves security by removing fallback on directory attributes, which might be altered by attackers. https://office365itpros.com/2026/06/17/sspr-authentication-methods/Microsoft Launches Container Management Support for Security Groups
A recent blog from the Microsoft Digital (IT department) discusses the preview implementation of container management labels for security groups. The implementation is limited because it encompasses just one control: the ability to have guest accounts in the membership of security groups. However, just that limited control is sufficient to stop unintended access to sensitive information by guest accounts, and that’s a very good thing. https://office365itpros.com/2026/06/03/security-groups-labels/Automating Microsoft 365 with PowerShell Second Edition
The Office 365 for IT Pros team are thrilled to announce the availability of Automating Microsoft 365 with PowerShell (2nd edition). This completely revised 350-page book delivers the most comprehensive coverage of how to use Microsoft Graph APIs and the Microsoft Graph PowerShell SDK with Microsoft 365 workloads (Entra ID, Exchange Online, SharePoint Online, Teams, Planner, and more). Existing subscribers can download the second edition now free of charge. https://office365itpros.com/2025/06/30/automating-microsoft-365-with-powershell2/
Web-signin 3rd party IDP not working
We have a working Entra ID SAML federation to a third-party IdP that uses FIDO2/WebAuthn (IdP as Relying Party) for browser sign-in, and we are trying to use the same federation through Windows Web sign-in on an Entra-joined Windows 11 device — but the IdP page loads blank in the WebView and Microsoft-Windows-WebAuthN/Operational records zero events, while the same security key works fine for FIDO2 sign-in with login.microsoft.com as RP on the same device. Questions: - Is WebAuthn brokering to third-party Relying Parties inside the Web sign-in WebView supported? - If not, is it on the roadmap? - What is the supported architectural path for delivering passwordless Windows sign-in using a federated IdP's own FIDO2/WebAuthn credentials, given Graph API passkey provisioning is Beta-only?
O365 Email Migration to Another Tenant while Deferring Migration of Sharepoint files
Hi, This is the context: ChildCompany has O365 and it has an Azure AD in hybrid mode synchronizing to a on-prem AD server. They have an internal domain ChildCompany.com, and an external domain ChildCompany.com where they also receive and send email using O365. ParentCompany is going absorb the ChildCompany some time in next year, and I was asked about the integration options. According to this https://download.microsoft.com/download/b/a/1/ba19dfe7-96e2-4983-8783-4dcff9cebe7b/microsoft-365-tenant-to-tenant-migration.pdf I could do a phased migration, where the end state is that they decomm their onprem AD and that they only use our ParentCompany systems. The business requirement is to start their integration with Email, and then in later phases do the Sharepoint integration as that requires way more analysis on their data sources, as they also have wikis and many other on prem legacy stuff. They are less than 50 users, so I can use Quest migration tools for the email part, but I wonder what needs to happen in what order. This is what I have in mind: Migrate their current O365 into our ParentCompany Office 365 subscription, so that they can continue logging in into their domain joined windows machines using childCompany.co, so they start using ParentCompany.com email addresses, but the problem then is how can they continue using their sharepoint and onedrive resources associated with the Azure and local domain at ChildCompany.com? This is more or less what I have in mind, for the intermediate step, the cutover: Child Company ParentCompany --------------------- ---------------- On-Prem | MS Cloud: | MS Cloud: ---------------|----------------------|-------------- Local AD (ADFS)| Azure Subscription | Azure Sub | Azure AD | Azure AD |--------------------- |--------------------- | O365 Sub -> | O365 Sub | Exchange mailboxes-> | Exchange mailboxes | Sharepoint? -> | ??? | -------------------- |--------------------- I wonder how could it be possible to defer the sharepoint and onedrive migration, so that the child company users can still work on their sharepoint files using their normal auth methods, while disabling childcompany.com as MX so they start using ParentCompany.com mailboxes.Is that even possible? Would make more sense to try to migrate everything at once? That is way more work, but I'm weighting my options.Entra Group Source of Authority CONVERSION: Enabling Cloud-First Identity Management
As organizations modernize their identity infrastructure, Microsoft Entra’s Group Source of Authority (SOA) Conversion feature enables a granular migration of group management from on-premises AD to Microsoft Entra ID without disabling sync or rearchitecting the entire directory. What Is Group Source of Authority? Group SOA defines where a group object is mastered either in on-prem AD or in Entra ID. With SOA conversion, administrators can selectively convert AD-synced groups into cloud-native groups, making them editable and governable directly in Entra ID. Permissions Required To perform SOA conversion, the following Microsoft Entra roles and Graph API permissions are required: Hybrid Administrator: Required to call Microsoft Graph APIs to read and update SOA of groups. Application Administrator or Cloud Application Administrator: Required to grant user consent to the app or Graph Explorer. Graph API Permission Scope: Group-OnPremisesSyncBehavior.ReadWrite.All must be granted to the app calling the onPremisesSyncBehavior endpoint. Prerequisites Before initiating SOA conversion, ensure the following: Licensing Microsoft Entra Free or Basic license is sufficient. Sync Clients Microsoft Entra Connect Sync: Minimum version 2.5.76.0 Microsoft Entra Cloud Sync: Minimum version 1.1.1370.0 Group Eligibility Groups must not be mail-enabled or tied to Exchange on-premises (DLs or MESGs). If provisioning back to AD is planned, change group scope to Universal. How to Convert Group SOA from AD to Entra Here’s a simplified step-by-step guide: Identify Target Groups Use Entra Admin Center or Graph Explorer to list synced groups. Confirm they are not Exchange-dependent. Grant Permissions Use Graph Explorer or your app registration to grant Group-OnPremisesSyncBehavior.ReadWrite.All. Execute SOA Conversion If we see Group1, which is in scope of conversion is synchronized from on-prem. Execute the below from Graph Explorer to convert “Group1” to cloud managed PATCH https://graph.microsoft.com/beta/groups/{group-id}/OnPremisesSyncbehavior { "isCloudManaged": true } We can verify the change by executing below query on Graph API Explorer This marks the group as cloud-managed. AD sync will stop honoring changes to this group. Validate Conversion Confirm blockOnPremisesSync = true in the Entra Admin Center. Use audit logs to verify the change. Apply Governance Apply lifecycle policies, access reviews, and provisioning rules using Entra ID Governance. Use Cases: Migrating from On-Prem to Cloud Use Case 1: Retiring Legacy AD Groups Scenario: A customer has migrated all mailboxes to Exchange Online and no longer needs certain AD groups. Solution: Convert those groups to cloud-native Entra ID groups and delete them from AD, reducing footprint and simplifying governance. Use Case 2: Governing On-Prem Apps from the Cloud Scenario: A customer uses AD security groups to secure on-prem apps (e.g., Kerberos-based apps). Solution: Convert the group SOA to Entra ID, apply governance policies, and use Group Provision to AD to sync cloud-managed groups back to AD. Use Case 3: Migrating DLs and MESGs to Cloud Scenario: A customer wants to migrate all distribution lists and mail-enabled security groups to the cloud. Solution: Convert SOA to Entra ID, recreate mail-enabled groups in Exchange Online, and decommission AD-based mail groups. Use Case 4: Enabling Access Reviews Scenario: A federal customer wants to run access reviews on group memberships but the groups are AD-synced. Solution: Convert SOA to Entra ID, enabling full access review capabilities and lifecycle workflows. Use Case 5: Hybrid Identity Cleanup Scenario: A customer is migrating from Entra Connect Sync to Cloud Sync and wants to clean up group sprawl. Solution: Use SOA conversion to move group management to the cloud, then decommission legacy sync rules and OUs. Strategic Impact Group SOA Conversion is more than a technical enhancement, it’s a strategic enabler for identity modernization. It supports: AD DS minimization: Shrinking on-prem footprint. Cloud-first governance: Centralized access control and lifecycle management. Phased migration: Avoiding disruption while modernizing.
