Job Description

We are seeking a hands-on Email Security Engineer to support the delivery and operational uplift of Optus email security. The contractor will work closely with Luc and the Director, Data Protection & Email Security, to strengthen outbound controls, complete Mimecast implementation activities and support the controlled decommissioning of Trend Micro email security capabilities.

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This is a delivery-focused role for someone who can operate at both engineering and operational levels — designing changes, implementing them, troubleshooting issues, documenting outcomes and handing over stable services to BAU teams.

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Key responsibilities

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- Execute configuration and engineering changes in a controlled manner.
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- Coordinate testing with technical teams and business stakeholders.
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- Develop runbooks, technical procedures, support models and knowledge-transfer materials.
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- Monitor post-change outcomes and recommend further tuning.
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- Escalate issues early and drive actions through to completion.
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- Design, implement and validate the Mimecast outbound mail flow.
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- Review outbound routing, controls, policies, authentication and delivery behaviour.
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- Identify and close gaps across data protection, malware, impersonation, URL and policy enforcement controls.
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- Troubleshoot mail-flow issues across Mimecast, Microsoft 365 and downstream or third-party systems.
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- Support testing, cutover planning, monitoring and rollback readiness.
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- Map current Trend Micro email security capabilities, integrations, dependencies and traffic flows.
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- Define the migration and decommissioning sequence in coordination with the Mimecast target state.
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- Remove or retire legacy configurations, rules and integrations safely.
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- Validate that required protection and mail-flow outcomes remain in place after each change.
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- Support defect resolution, rollback planning, evidence capture and final closure of the decommissioning work.
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- Solid hands-on experience administering and engineering Email Security.
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- Demonstrated experience with outbound email security and enterprise mail-flow troubleshooting.
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- Practical experience implementing email journaling and validating message coverage.
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- Experience uplifting email security policies and managing controlled exceptions.
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- Experience with Microsoft 365 / Exchange Online mail flow, connectors, transport rules and message tracing.
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- Experience retiring or migrating legacy email security platforms, preferably Trend Micro.
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- Working knowledge of SPF, DKIM, DMARC, SMTP, DNS and email authentication.
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- Ability to produce clear technical documentation and operational handover material.
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📌 Email Security Engineer - NCS Australia (New South Wales)
🏢 Polluxa
📍 New South Wales