Senior Messaging Lead

The Senior Messaging Lead is responsible for the operation, security, support and continuous improvement of K ’s enterprise messaging environment. The role provides technical leadership for Microsoft Exchange Online, supported Exchange Server hybrid components, enterprise mail flow, Microsoft Defender for Office 365, Abnormal Security and messaging-related integrations with Microsoft 365 and Microsoft Entra  successful candidate will act as the highest level of technical escalation for complex messaging, mailbox and Outlook-related service issues.

They will also line manage one messaging administrator responsible for day-to-day support and administration. The role works closely with Cybersecurity, Security Operations, Identity and Access Management, Workplace Technology, Service Management, Legal, Privacy and Compliance teams.

• Provide senior technical leadership for Exchange Online, Exchange hybrid services, enterprise mail flow and assigned email security platforms.
• Line manage, coach and develop one messaging administrator, including work allocation, objective setting and performance management.
• Administer and support mail flow, connectors, accepted domains, transport rules, SMTP relay services, shared mailboxes, resource mailboxes and mail-enabled groups.
• Maintain supported Exchange hybrid services, including mail routing, certificates, authentication dependencies and Autodiscover.
• Monitor Microsoft 365 service health, planned changes, feature retirements and relevant Message Centre notifications.
• Administer Microsoft Defender for Office 365 controls, including Safe Links, Safe Attachments, anti-phishing policies, Threat Explorer and Automated Investigation and Response.
• Administer and support Abnormal Security and the technical integration of the KnowBe4 Phish Alert Button.
• Investigate and remediate email-borne threats in partnership with Cybersecurity and Security Operations.
• Serve as the senior technical escalation point for complex Outlook, mailbox, calendar, authentication, connectivity and messaging policy issues.
• Support messaging-related Microsoft Entra application registrations, service principals, API permissions, OAuth and Microsoft Graph integrations.
• Ensure messaging-related application permissions follow least-privilege and established approval processes.
• Support approved messaging retention, legal hold, eDiscovery and compliance requirements in partnership with Legal, Privacy, Compliance and Records Management teams.
• Lead or support major messaging incidents, root cause analysis, corrective actions and service recovery.
• Develop secure Power Shell and Microsoft Graph automation for messaging administration, reporting and service health monitoring.
• Maintain accurate operational documentation, technical standards, support procedures, service records and knowledge articles.
• Manage technical relationships and escalations with Microsoft, Abnormal Security, KnowBe4 and other relevant suppliers.

• You will have substantial experience supporting enterprise messaging services within 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 and email security operations.
• Strong knowledge of enterprise mail flow, connectors, transport rules, SMTP relay, authentication and Autodiscover.
• Strong Microsoft Outlook and mailbox troubleshooting capability.
• Experience with Microsoft Entra , application registrations, service principals, OAuth and API permissions relevant to messaging.
• Strong Exchange Online Power Shell skills and experience using Microsoft Graph or comparable…