Senior Messaging Lead (Microsoft Exchange)

Location: Leatherhead Campus, United Kingdom, with hybrid working arrangements. The role supports global services across multiple regions and time zones; occasional work outside normal UK business hours and limited UK or international travel may be required. The successful candidate must have the right to work in the United Kingdom and may need to obtain and maintain an appropriate level of security clearance.

Company

hirify.global provides engineering, technology, and lifecycle solutions to government and industry clients, with a focus on safety, reliability, sustainability, and complex missions.

What you will do

• Lead the operation, security, support, and continuous improvement of Exchange Online, hybrid Exchange services, enterprise mail flow, and email security platforms.
• Administer connectors, accepted domains, transport rules, SMTP relay services, shared and resource mailboxes, mail-enabled groups, certificates, authentication dependencies, and Autodiscover.
• Administer Microsoft Defender for Office 365, Abnormal Security, and the KnowBe4 Phish Alert Button integration while investigating and remediating email-borne threats.
• Act as the highest-level escalation point for complex Outlook, mailbox, calendar, authentication, connectivity, and messaging policy issues.
• Support Microsoft Entra ID application registrations, service principals, OAuth, API permissions, Microsoft Graph integrations, retention, legal hold, eDiscovery, and compliance requirements.
• Lead major messaging incidents, root cause analysis, corrective actions, service recovery, documentation, and supplier escalations.

Requirements

• Substantial experience supporting enterprise messaging services in a large, complex, or regulated organisation.
• Deep hands-on experience administering Microsoft Exchange Online and supported Exchange Server hybrid environments.
• Advanced experience with Microsoft Defender for Office 365, email security operations, enterprise mail flow, authentication, and Outlook troubleshooting.
• Experience with Microsoft Entra ID dependencies, application registrations, service principals, OAuth, API permissions, Exchange Online PowerShell, and Microsoft Graph or comparable APIs.
• Experience leading major incidents, problem management, root cause analysis, and technical mentoring or line management.
• Right to work in the United Kingdom; willingness to meet applicable security clearance requirements and work occasional non-standard UK hours.

Nice to have

• Experience with Abnormal Security, KnowBe4, Microsoft Purview, global Microsoft 365 environments, or highly regulated organisations.
• Relevant Microsoft and ITIL qualifications.

Culture & Benefits

• Hybrid working based at the Leatherhead Campus under the applicable company policy and operational requirements.
• Work on global services supporting multiple regions and time zones.
• Competitive benefits and professional development opportunities.
• Collaborative environment focused on creativity, resourcefulness, safety, reliability, and meaningful client outcomes.