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.