Senior M365 Engineer

Responsibilities Exchange Online, email security and delivery Manage Exchange Online, including hybrid Exchange, mail flow, connectors and migrations. Configure email security: SPF, DKIM, DMARC, Defender for Office 365 and anti-phishing policies.

Own resolution of email delivery issues: bounces and NDRs, delayed or missing mail, messages wrongly sent to junk or quarantine, and inbound/outbound blocking. Investigate with message trace, message headers, quarantine and Exchange admin center reports. Monitor sender reputation and handle blocklist delisting (e. g.

Microsoft, Spamhaus) and third-party mail gateway or relay issues. Manage DNS records for mail (MX, SPF, DKIM, DMARC, Autodiscover) and review DMARC reports to prevent spoofing and delivery failures. Teams, SharePoint and OneDrive Administer Teams, including policies, governance, Teams Phone and meeting rooms.

Design SharePoint Online and OneDrive structure, permissions, sharing and lifecycle policies. Security policies, identity and compliance Design, implement and maintain Microsoft 365 security policies aligned to Microsoft and CIS security baselines.

Configure Defender for Office 365 policies: Safe Links, Safe Attachments, anti-phishing, anti-spam and anti-malware. Enforce Conditional Access policies: MFA for all users, blocking legacy authentication, and location and device-compliance rules. Set external sharing, guest access and Teams/SharePoint security policies.

Configure audit logging, alert policies and app protection policies for Outlook and Teams on mobile devices. Administer Entra ID: hybrid identity (Entra Connect), Conditional Access, MFA and PIM. Implement Microsoft Purview: data loss prevention, sensitivity labels, retention and eDiscovery.

Monitor and improve Microsoft Secure Score and respond to security alerts. Operations Automate administration and reporting with PowerShell and Microsoft Graph. Manage licences, service health, change management and vendor support cases. Keep documentation, runbooks and user guidance up to date.

Required Qualifications 7+ years in Microsoft infrastructure, including 5+ years administering Microsoft 365 at enterprise scale (1,000+ users). Proven experience leading Exchange and tenant-to-tenant migrations. Deep knowledge of Exchange Online, Teams, SharePoint Online and OneDrive.

Strong Entra ID, Conditional Access and hybrid identity experience. Hands-on experience with Purview compliance and Defender for Office 365. Strong PowerShell skills, including Microsoft Graph. Experience leading projects, mentoring engineers and working with senior stakeholders.

Proven track record troubleshooting complex email delivery issues using message trace, headers, NDR codes and DNS mail records. Hands-on experience designing and implementing Microsoft 365 security policies (Defender for Office 365, Conditional Access, sharing and audit policies) in an enterprise tenant.

Preferred Qualifications

Area Certification Microsoft 365 MS-102 Microsoft 365 Administrator Expert Teams MS-700 Teams Administrator Identity SC-300 Identity and Access Administrator Security / compliance SC-401 Information Security Administrator, or SC-200