Microsoft 365 Exchange Online SME
Posted Today by Brillio Europe Limited
Negotiable
Outside
Remote
London, UK
Summary: The role of Microsoft 365 Exchange Online SME involves providing expert knowledge in Microsoft 365 Exchange Online, focusing on troubleshooting and resolving complex issues related to hybrid migrations and EWS-based integrations. The position requires a deep understanding of Exchange Online architecture and the ability to restore functionality post-migration, ensuring seamless integration with Outlook and Office add-ins. The SME will also be responsible for validating configurations and providing technical guidance to regional IT teams. This role is remote but may require late-night work for global changes.
Key Responsibilities:
- Diagnose failures in Exchange Online services and client integrations, including EWS-dependent add-ins, Outlook connectivity, and mailbox operations.
- Conduct end-to-end tracing of EWS authentication and service calls across Exchange Online, Outlook desktop, Outlook on the web, and regional tenants.
- Compare working versus non-working regions to identify issues linked to Conditional Access, Client Access Rules, hybrid remnants, or policy misalignment.
- Correlate Exchange Online and Entra ID sign-in logs to identify authentication or Conditional Access-related failures.
- Review and correct EWS Application Access Policies, Allow/Block Lists, and Client Access Rules at tenant level.
- Validate and re-enable EWS at both mailbox and organization level.
- Identify and remove hybrid Exchange remnants, including obsolete Remote Mailbox, AuthServer, and IntraOrganizationConnector objects.
- Audit and correct Autodiscover, DNS, and service connection points to ensure cloud authority.
- Re-deploy and verify Office add-ins via Centralized Deployment or Integrated Apps to ensure alignment with Exchange Online.
- Review and rationalize Conditional Access policies, Named Locations, and network egress configurations affecting Exchange Web Services.
- Use native and PowerShell tools such as Test-WebServicesConnectivity, Outlook Auto Configuration, and Connection Status to confirm successful EWS communication.
- Validate mailbox stamping, license assignment, and add-in manifest retrieval post-remediation.
- Develop PowerShell or Graph-based scripts to monitor tenant-wide EWS health.
- Produce detailed documentation of the environment, changes applied, and final configuration baseline.
- Provide technical guidance to regional IT teams on maintaining Exchange Online and add-in stability.
- Deliver runbooks and knowledge articles for recurring health checks and troubleshooting.
Key Skills:
- Deep understanding of Exchange Online architecture, hybrid coexistence, and mailbox migration.
- Advanced knowledge of Exchange Web Services, Outlook protocols, Autodiscover, and add-in dependencies.
- Strong grasp of Entra ID, OAuth2, Modern Auth, Conditional Access, and Client Access Rules.
- Skilled in Exchange Online cmdlets (Get/Set-CASMailbox, Get-OrganizationConfig, Get-ClientAccessRule, Test-WebServicesConnectivity).
- Ability to audit and correct EWS Application Access Policies, Allow/Block Lists, and hybrid trust relationships.
- Understanding of Tenant Restrictions, Proxy and Firewall configurations, and Microsoft 365 multi-geo routing.
- Practical experience deploying and validating Office add-ins through Centralized Deployment or Integrated Apps.
- Ability to perform structured RCA, communicate clearly, and document fixes for cross-team use.
- Desirable certifications: Microsoft Certified: Exchange Online Administrator Associate (MS-203), Microsoft Certified: Identity and Access Administrator Associate (SC-300), Microsoft Certified: Modern Desktop Administrator Associate (MD-102), ITIL v4 Foundation (or equivalent operational framework).
- Analytical, detail-oriented problem solver able to isolate tenant-level versus mailbox-level issues.
- Strong communicator capable of explaining complex technical outcomes to stakeholders.
- Comfortable working across multiple regions and coordinating with security and operations teams.
- Produces clear documentation and structured remediation plans.
Salary (Rate): undetermined
City: London
Country: UK
Working Arrangements: remote
IR35 Status: outside IR35
Seniority Level: undetermined
Industry: IT
Job Title:
Microsoft 365 Exchange Online SME
Location:
Remote/Open to working late nights when required (for global changes etc)
Overview
We are seeking a subject matter expert (SME) with deep experience in Microsoft 365 Exchange Online, hybrid Exchange migrations, and EWS-based integrations to troubleshoot, diagnose, and remediate complex connectivity and configuration issues across a multi-regional tenant.
The SME will focus on restoring full Exchange Online functionality following hybrid migration, including Outlook and Office add-in integration, authentication flow, and tenant-level configuration drift.
Key Responsibilities
Investigation and Root Cause Analysis
- Diagnose failures in Exchange Online services and client integrations, including EWS-dependent add-ins, Outlook connectivity, and mailbox operations.
- Conduct end-to-end tracing of EWS authentication and service calls across Exchange Online, Outlook desktop, Outlook on the web, and regional tenants.
- Compare working versus non-working regions to identify issues linked to Conditional Access, Client Access Rules, hybrid remnants, or policy misalignment.
- Correlate Exchange Online and Entra ID sign-in logs to identify authentication or Conditional Access-related failures.
Remediation and Configuration
- Review and correct EWS Application Access Policies, Allow/Block Lists, and Client Access Rules at tenant level.
- Validate and re-enable EWS at both mailbox and organization level.
- Identify and remove hybrid Exchange remnants, including obsolete Remote Mailbox, AuthServer, and IntraOrganizationConnector objects.
- Audit and correct Autodiscover, DNS, and service connection points to ensure cloud authority.
- Re-deploy and verify Office add-ins via Centralized Deployment or Integrated Apps to ensure alignment with Exchange Online.
- Review and rationalize Conditional Access policies, Named Locations, and network egress configurations affecting Exchange Web Services.
Validation and Testing
- Use native and PowerShell tools such as Test-WebServicesConnectivity, Outlook Auto Configuration, and Connection Status to confirm successful EWS communication.
- Validate mailbox stamping, license assignment, and add-in manifest retrieval post-remediation.
- Develop PowerShell or Graph-based scripts to monitor tenant-wide EWS health.
Governance and Knowledge Transfer
- Produce detailed documentation of the environment, changes applied, and final configuration baseline.
- Provide technical guidance to regional IT teams on maintaining Exchange Online and add-in stability.
- Deliver runbooks and knowledge articles for recurring health checks and troubleshooting.
Key Skills and Experience
Area
Required Expertise
Exchange Online & Hybrid
Deep understanding of Exchange Online architecture, hybrid coexistence, and mailbox migration.
EWS/Outlook Integration
Advanced knowledge of Exchange Web Services, Outlook protocols, Autodiscover, and add-in dependencies.
Authentication & Security
Strong grasp of Entra ID, OAuth2, Modern Auth, Conditional Access, and Client Access Rules.
PowerShell Diagnostics
Skilled in Exchange Online cmdlets (Get/Set-CASMailbox, Get-OrganizationConfig, Get-ClientAccessRule, Test-WebServicesConnectivity).
Tenant Configuration
Ability to audit and correct EWS Application Access Policies, Allow/Block Lists, and hybrid trust relationships.
Networking/Multi-Geo Awareness
Understanding of Tenant Restrictions, Proxy and Firewall configurations, and Microsoft 365 multi-geo routing.
Office Add-in Troubleshooting
Practical experience deploying and validating Office add-ins through Centralized Deployment or Integrated Apps.
Incident Response & Documentation
Ability to perform structured RCA, communicate clearly, and document fixes for cross-team use.
Desirable Certifications
- Microsoft Certified: Exchange Online Administrator Associate (MS-203)
- Microsoft Certified: Identity and Access Administrator Associate (SC-300)
- Microsoft Certified: Modern Desktop Administrator Associate (MD-102)
- ITIL v4 Foundation (or equivalent operational framework)
Soft Skills
- Analytical, detail-oriented problem solver able to isolate tenant-level versus mailbox-level issues.
- Strong communicator capable of explaining complex technical outcomes to stakeholders.
- Comfortable working across multiple regions and coordinating with security and operations teams.
- Produces clear documentation and structured remediation plans.
Success Criteria
- EWS connectivity restored and validated across all regions.
- Office add-ins load and function correctly for all users.
- Conditional Access, Client Access Rules, and EWS policies rationalized and documented.
- Hybrid Exchange remnants fully removed and tenant configuration aligned to cloud-only best practice.
- Runbooks and health checks delivered to ensure long-term stability.