Security Engineer - Email Security

Zelis is seeking a Security Engineer focused on email security to help protect and improve the security, reliability, and resilience of its enterprise email environment. The role centers on detecting and preventing email-based threats, administering email security controls in Microsoft 365, and supporting incident investigation and remediation.

Key Responsibilities

• Conduct in-depth analysis of suspicious messages, including review of email headers, message routing, URLs, attachments, sender reputation, authentication outcomes, and other indicators of compromise.
• Administer and support email security controls within Exchange Online, Defender for O365, EasyDMARC, and Abnormal Security.
• Troubleshoot issues related to email delivery, mail flow, quarantine, filtering, and email security policy behavior.
• Review Exchange message traces and mail-flow logs to assess message disposition and identify delivery or security concerns.
• Configure and maintain mail-flow rules, anti-spam policies, anti-phishing protections, allow/block lists, quarantine policies, and related security controls.
• Support incident containment and remediation activities, including message removal, sender and domain blocking, URL blocking, mailbox remediation, and escalation of compromised accounts.
• Assist with administration and tuning of Microsoft Defender for Office 365 or comparable secure email gateway and email security technologies.
• Analyze and troubleshoot email authentication mechanisms, including SPF, DKIM, and DMARC.
• Identify false positives and false negatives and recommend improvements to email security policies and detection rules.
• Document investigations, findings, remediation actions, and recurring email security issues.
• Create and maintain operational procedures, troubleshooting guides, and knowledge-base documentation.
• Collaborate with SOC, Incident Response, Identity and Access Management, Infrastructure, and Messaging teams during security investigations.
• Support email security metrics, reporting, trend analysis, and continuous improvement efforts.
• Stay current with emerging phishing techniques, business email compromise tactics, attacker infrastructure, and email security best practices.

Required Qualifications

• 5+ years of proven experience designing and implementing enterprise-grade email security guardrails in regulated fintech or healthcare environments, with a strong security-first mindset and demonstrated expertise in phishing and BEC prevention, email authentication, data loss prevention, policy enforcement, monitoring, and incident response.
• 3+ years of hands-on experience with Microsoft Exchange, Exchange Online, or Microsoft 365 messaging environments.
• Working knowledge of Microsoft Exchange mail flow, connectors, transport/mail-flow rules, and message tracking and tracing.
• Experience investigating phishing, spam, malware, spoofing, and business email compromise incidents.
• Strong understanding of email protocols and technologies, including SMTP, DNS, SPF, DKIM, and DMARC.
• Experience analyzing email headers to determine message origin, routing, authentication results, and possible indicators of malicious activity.
• Familiarity with Microsoft Defender for Office 365, Exchange Online Protection (EOP), or similar enterprise email security platforms.
• Understanding of common attacker techniques involving credential phishing, malicious attachments, malicious URLs, impersonation, and account compromise.
• Strong analytical, troubleshooting, documentation, and communication skills.
• Ability to independently investigate moderately complex incidents and escalate high-risk or advanced threats appropriately.

Technologies

• Microsoft 365, Microsoft Exchange, Exchange Online, Exchange Online Protection (EOP)
• Defender for O365, Microsoft Defender for Office 365
• EasyDMARC, Abnormal Security
• SPF, DKIM, DMARC, SMTP, DNS
• PowerShell, PowerShell for Exchange Online administration, investigation, or automation
• Microsoft Purview, Microsoft Sentinel
• Microsoft Defender for Endpoint
• Proofpoint, Mimecast, Cisco Secure Email
• PowerShell / Security Automation

Benefits

• 401k plan with employer match
• Flexible paid time off
• Holidays
• Parental leaves
• Life and disability insurance
• Health benefits including medical, dental, vision, and prescription drug coverage

Preferred Qualifications

• Experience with Microsoft Defender for Office 365, including Safe Links, Safe Attachments, Threat Explorer, automated investigation and response, and related capabilities.
• Experience using Microsoft Purview, Microsoft Sentinel, or the Microsoft Defender security ecosystem.
• Experience with PowerShell for Exchange Online administration, investigation, or automation.
• Familiarity with other Microsoft tools; Defender for Endpoint and Purview included, for administration, monitoring, and policy tuning of EDR/XDR platforms.
• Experience investigating compromised Microsoft 365 accounts and malicious inbox or forwarding rules.
• Knowledge of email security gateways or platforms such as Proofpoint, Mimecast, Cisco Secure Email, Abnormal Security, or similar technologies.
• Familiarity with threat intelligence concepts, indicators of compromise (IOCs), and attacker tactics, techniques, and procedures (TTPs).
• Knowledge of AI/ML security concepts and emerging threats, data leakage, model abuse, identity and access controls, secure integrations, and protection of sensitive data within AI-enabled systems.

Location and Workplace Flexibility

• Morristown, NJ (hybrid).
• Zelis is headquartered in the U.S. with multiple locations across the country and in Hyderabad, India.
• Work location is based on the needs of the position and determined by Leadership.
• In-office work and activities vary based on team and business objectives in line with Company policies.
• Candidates within approximately 50 miles of a U.S. office are generally preferred to support collaboration when needed.
• Hybrid approach is flexible; in-office presence is guided by team and business needs rather than a fixed weekly schedule.

Base Salary Range

$135,200.00 - $185,900.00 per year.

Accessibility Support

For reasonable accommodation with any part of the application and/or interview process, email [email protected].