Senior Enterprise Messaging Architect

KBR, Inc.; Leatherhead; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

KBR, Inc. is seeking a Senior Messaging Lead to run the enterprise messaging environment, including Exchange Online, hybrid components and mail security.

You will lead a messaging team, manage mail flow, and drive security and compliance across Microsoft 365 services. You will collaborate with Cybersecurity, Legal, Privacy and Records teams, ensuring secure, reliable messaging operations and timely responses to incidents.

Qualifications

• Deep hands-on experience with Exchange Online and hybrid environments.
• Advanced experience with Defender for Office 365 and email security operations.
• Strong knowledge of mail flow, connectors, transport rules, SMTP relay, authentication and Autodiscover.
• Strong Outlook and mailbox troubleshooting skills.
• Experience with Entra ID dependencies, service principals and API permissions.

Responsibilities

• Provide senior technical leadership for Exchange Online, hybrid services and enterprise mail flow.
• Line manage one messaging administrator and set objectives.
• Administer mail flow, domains, transport rules, SMTP relay and mail-enabled groups.
• Maintain Exchange hybrid services, routing, certificates and Autodiscover dependencies.
• Monitor 365 service health, changes, and notifications.
• Administer Defender for Office 365 controls and security policies.
• Support Abnormal Security and KnowBe4 integrations and security incidents.
• Investigate and remediate email-borne threats with Cybersecurity teams.
• Serve as senior escalation point for Outlook, mailbox, and policy issues.
• Support Entra registrations, OAuth and API permissions for messaging.

Skills

Exchange Online administration

PowerShell

Microsoft Graph

Email security operations

Incident management

Education

Relevant Microsoft ITIL qualifications

Job description

KBR, Inc. is seeking a Senior Messaging Lead to run the enterprise messaging environment, including Exchange Online, hybrid components and mail security.

You will lead a messaging team, manage mail flow, and drive security and compliance across Microsoft 365 services. You will collaborate with Cybersecurity, Legal, Privacy and Records teams, ensuring secure, reliable messaging operations and timely responses to incidents.