Microsoft 365 Senior Engineer (L3)

Required Skills & Qualifications

Technical Skills

• Strong experience with:
  • Microsoft Exchange Online
  • SharePoint Online
  • OneDrive for Business
  • Microsoft Teams
  • Microsoft Teams Voice
• Experience with:
  • Microsoft Defender (Email & Threat Protection)
  • Microsoft Purview (Compliance & Retention)
  • Proofpoint Email Security
• Knowledge of:
  • SMTP mail flow
  • SPF DKIM DMARC
  • Email and security threat analysis

Role Overview

We are looking for an experienced Microsoft 365 Senior Engineer (L3) to support and manage enterprise collaboration messaging and security platforms. This role will act as the highest level of technical escalation handling complex issues security incidents and compliance requirements across Microsoft 365 and email security systems.

The ideal candidate will have strong hands on experience with Microsoft 365 services email security compliance and threat management and will work closely with IT Security and Compliance teams to ensure platform stability and data protection.

Key Responsibilities

Microsoft 365 Operations & Support

• Provide Level 3 (L3) support for Microsoft 365 services.
• Troubleshoot and resolve complex issues related to:
  • Exchange Online (email mail flow shared mailboxes)
  • SharePoint Online and OneDrive (access permissions data retention)
  • Microsoft Teams (chat meetings collaboration)
• Act as an escalation point for critical incidents and service disruptions.
• Perform root cause analysis (RCA) and recommend long term fixes.

Security Compliance & Governance

• Support Microsoft Purview (Compliance) features including:
  • Retention policies and labels
  • Audit and eDiscovery
  • Data Loss Prevention (DLP)
• Ensure compliance with organizational and regulatory requirements.
• Support governance processes related to data lifecycle and retention.

Email Security & Threat Management

• Manage and support Microsoft Defender for Office 365.
• Monitor investigate and respond to:
  • Threat alerts
  • Phishing and malware incidents
  • Account compromise attempts
• Administer and support Proofpoint Email Security including phishing response and policy tuning.
• Assist with protection of high risk / VIP users.

Email Infrastructure & DNS

• Manage and troubleshoot:
  • SMTP relay configurations
  • Email routing and connectors
• Support and maintain email authentication standards:
  • SPF
  • DKIM
  • DMARC
• Analyze email headers and delivery issues.

Collaboration & Reporting

• Work closely with Security Compliance and Infrastructure teams.
• Prepare:
  • Incident reports
  • RCA documentation
  • Operational and compliance reports
• Provide guidance and knowledge transfer to L1/L2 support teams.