M365 Messaging & Exchange Migration Lead

Jobtailor; Greater London; On-site; GBP 60,000 - 90,000; Full time

Job summary

Jobtailor is seeking an experienced Exchange Online and Microsoft 365 messaging specialist to lead mailbox migrations, configure mail-flow controls, and implement secure coexistence between messaging environments. The role emphasizes PowerShell automation, migration tooling, and strong documentation skills.

You will design, implement and validate mail routing, DNS/Autodiscover configurations, and drive pilot-to-production migrations with hands-on troubleshooting across Outlook and mobile

Qualifications

• Extensive hands-on experience with Exchange Online and Microsoft 365 messaging.
• Proven mailbox migrations within complex enterprise environments.
• Experience with tenant-to-tenant and hybrid Exchange migrations at scale.
• Strong understanding of Exchange Online architecture and administration.
• Knowledge of DNS, Autodiscover and SMTP relay.
• Experience managing mailbox permissions and distribution groups.
• PowerShell automation for configuration, migration, validation and reporting.
• Knowledge of Defender for Office 365, email security and compliance.
• Experience supporting messaging migrations through pilot, production and cutover.
• Excellent documentation and runbook creation skills.

Responsibilities

• Configure and manage Exchange Online and Microsoft 365 messaging services according to approved architecture.
• Design, implement and troubleshoot mail-routing configurations across environments.
• Configure and manage connectors, domains, transport rules and mail-flow settings.
• Establish secure coexistence between messaging environments and migrations across waves.
• Develop migration plans, readiness checks and automation scripts.
• Validate mailbox permissions, calendars, delegates and distribution groups.
• Test and support Outlook/mobile access and client behavior.
• Implement DNS changes and Autodiscover/SMTP relay configurations.
• Provide early-life support and create runbooks and knowledge-transfer materials.

Skills

Exchange Online

Mailbox Migration

PowerShell

Microsoft 365

Mail Flow

DNS Management

Tenant-to-Tenant Migration

Hybrid Exchange

Security & Defender

Tools

Migration Tooling

Outlook/Desktop Clients

Migration Planning Tools

Job description

Jobtailor is seeking an experienced Exchange Online and Microsoft 365 messaging specialist to lead mailbox migrations, configure mail-flow controls, and implement secure coexistence between messaging environments. The role emphasizes PowerShell automation, migration tooling, and strong documentation skills.

You will design, implement and validate mail routing, DNS/Autodiscover configurations, and drive pilot-to-production migrations with hands-on troubleshooting across Outlook and mobile