Security Engineer - Email Security

About the role

Zelis is seeking a Security Engineer - Email Security to support and enhance the security, reliability, and protection of our enterprise email environment. This role will focus on identifying and preventing email-based threats, administering email security controls, troubleshooting mail-flow and security issues, and supporting Microsoft 365/Exchange Online environments. The ideal candidate has hands-on experience with Microsoft Exchange, email security technologies, phishing investigations, mail-flow analysis, and security incident response. This individual will work closely with Security Operations, Messaging/Infrastructure, Identity, and other technology teams to protect the organization from phishing, business email compromise (BEC), malware, spoofing, and other email-based threats.

Responsibilities

• Perform detailed analysis of suspicious messages, including email headers, message routing, URLs, attachments, sender reputation, authentication results, and other indicators of compromise.
• Administer and support email security controls within Exchange Online, Defender for O365, EasyDMARC, and Abnormal Security environments.
• Troubleshoot email delivery, mail-flow, quarantine, filtering, and security-policy issues.
• Review and analyze Exchange message traces and mail-flow logs to determine message disposition and identify security or delivery issues.
• Configure and maintain mail-flow rules, anti-spam policies, anti-phishing protections, allow/block lists, quarantine policies, and related email security controls.
• Support incident containment and remediation activities, including message removal, sender/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/email security technologies.
• Analyze and troubleshoot email authentication technologies 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.
• Assist with email security metrics, reporting, trend analysis, and continuous improvement initiatives.
• Stay current on emerging phishing techniques, business email compromise tactics, attacker infrastructure, and email security best practices.

Requirements

• 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 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, message tracking