Senior M365 Engineer

Randstad Technologies Recruitment; Greater London; On-site; GBP 111,000 - 166,000; Full time

Job summary

Randstad Technologies Recruitment in London is seeking a Senior Microsoft 365 Engineer to join our global engineering team. You will own administration of Exchange Online, Teams, SharePoint Online, and related services, acting as the local SME for the London environment.

You will lead security, compliance, and migration initiatives including Mimecast to Microsoft 365, and collaborate on M365 architecture with Copilot-enabled features. This is a 6-month contract with potential extension.

Qualifications

• 8+ years of IT experience focused on Microsoft 365 platform engineering.
• 5+ years administering Exchange Online in large enterprise environments.
• Deep knowledge of mail flow, transport rules, and messaging security.
• Experience managing Azure AD / Entra ID and Intune.
• Experience with SharePoint Online, Teams, and OneDrive.
• Experience implementing M365 compliance features (retention policies, eDiscovery).
• Experience with Mimecast, Proofpoint, or similar security platforms.
• Bonus: PowerShell scripting and automation.
• Experience in large regulated environments.

Responsibilities

• Administer and optimize Exchange Online, Teams, SharePoint Online, and OneDrive.
• Act as London local M365 SME in governance and strategy.
• Configure Exchange Online mail flow and routing.
• Support Mimecast to Microsoft 365 migration and related migrations.
• Implement retention, eDiscovery, and compliance policies.
• Collaborate on M365 architecture and new features like Copilot.
• Monitor service health and handle advanced escalations.

Skills

Microsoft 365

Exchange Online

Azure AD / Entra ID

Intune

SharePoint Online

Teams

OneDrive

M365 compliance

Mimecast

Proofpoint

PowerShell scripting

Tools

Mimecast

Proofpoint

Job description

Adword

Job Title: Senior Microsoft 365 Engineer

Location: London, UK

Job Type: 06 months contract with a possibility of extension

About the Role

Are you an experienced Microsoft 365 professional with deep expertise in Exchange Online and enterprise messaging?

We are looking for a Senior Microsoft 365 Engineer to support, secure, and enhance our global Microsoft 365 environment. Serving as our London-based Subject Matter Expert (SME), you will work closely with our global engineering team to drive platform optimization, messaging security, and high-impact migration initiatives.

In this role, you will be at the forefront of our collaboration and security strategy-from implementing M365 compliance policies to assisting with a major Mimecast to Microsoft 365 migration. If you are passionate about platform-level engineering and ready to take ownership of enterprise-scale M365 services, we want to hear from you.

Key Responsibilities

• Core Administration: Administer, support, and optimize core Microsoft 365 services, including Exchange Online, Teams, SharePoint Online, and OneDrive.
• Subject Matter Expertise: Act as the local M365 technical SME in London, actively participating in governance, strategy, and stakeholder meetings.
• Messaging & Mail Flow: Support, configure, and troubleshoot complex Exchange Online mail flow, routing, and messaging services.
• Migration Projects: Play a key role in email security and migration projects, specifically an upcoming Mimecast to Microsoft 365 migration, as well as OneDrive and file migration initiatives.
• Security & Compliance: Implement and maintain robust retention, eDiscovery, and compliance policies to meet regulatory standards.
• Innovation & Architecture: Collaborate with global teams on M365 architecture improvements and the adoption of cutting-edge features, including Microsoft Copilot.
• Escalation & Monitoring: Monitor M365 service health, resolve advanced escalated incidents, and provide authoritative guidance on security and best practices.

Required Experience

• 8+ years of progressive IT experience, with a strong, dedicated focus on Microsoft 365 platform engineering.
• 5+ years of hands-on experience administering Exchange Online in large-scale enterprise environments.
• Deep technical knowledge of mail flow, transport rules, and enterprise messaging security.
• Proven experience managing Azure AD / Entra ID and Intune.
• Strong background supporting and configuring SharePoint Online, Teams, and OneDrive.
• Hands-on experience implementing M365 compliance features (retention policies, eDiscovery, etc.).
• Experience working with enterprise email security platforms such as Mimecast, Proofpoint, or similar.
• Bonus: Strong PowerShell scripting and automation capabilities are highly desirable.
• Previous experience working in large enterprise or strictly regulated environments.

Is This Role Right For You?

Please Note: This is a highly specialized, platform-level Microsoft 365 engineering position focusing heavily on Exchange Online and backend messaging services.