RHEL Engineer-Mailflow

The NASA IT portfolio with Digital Modernization Sector currently has an opening for a RHEL Engineer-Mailflow to manage and maintain our Red Hat Enterprise Linux (RHEL) servers and M365 collaboration services as well as supporting enterprise email services.

This is a telework position, but the ideal candidate will reside within reasonable commute distance from a NASA operating center (Johnson Space Center (Houston, TX) or Marshall Space Flight Center (Huntsville, AL)).

This is an exciting opportunity to use your experience helping the NASA End-User Services and Technologies (NEST) mission. In this mission, we serve as an agile, trusted partner to transform, integrate, simplify, modernize, and safeguard NASA IT systems and data. And, above all else, continuously enhance the end-user experience.

The RHEL Engineer is responsible for supporting and enhancing the mail flow environment at NASA to include M365 and on-premises infrastructure. This infrastructure includes Red Hat Enterprise Linux-based Postfix servers, Exchange Server SE, Exchange Online, Microsoft Teams, Microsoft Defender and the M365 Security Suite, SMTP gateways, email authentication standards (SPF, DKIM, and DMARC), and ensuring high availability through multi-site load balancing and system hardening.

Having a strong technical background in these technologies will be key for the successful candidate. The ideal candidate will have deep technical expertise in Linux systems, email security, and automation. Must be able to clearly articulate technical dialog with a variety of audiences to include NEST and NASA management.

Key Responsibilities

• Email Security & Authentication:
  • Implement and monitor SPF, DKIM, and DMARC policies.
  • Troubleshoot email delivery issues and enforce anti-spoofing measures.
• Linux Server Administration:
  • Full lifecycle management of our Red Hat servers, including installation, configuration and patching in production and test environments.
  • Perform security patching, upgrades, and hardening to meet compliance standards and remediate critical vulnerabilities
• Email Infrastructure Management:
  • Configure and maintain Postfix SMTP servers for enterprise email flow.
  • Integrate email services with DNS, LDAP, and TLS for secure delivery.
• Load Balancing & High Availability:
  • Knowledge of load balancers and DNS for email services.
  • Support failover and disaster recovery strategies.
• Monitoring & Troubleshooting:
  • Use tools like Grafana, Nagios, Zabbix, or similar for system and service monitoring.
  • Analyze logs and resolve complex SMTP and network issues.
• Automation & Scripting:
  • Automate routine tasks using Bash, Python, PowerShell, and configuration management tools (Ansible, Puppet).
  • Maintain accurate documentation of configurations and processes.
• Microsoft 365 Tenant Management:
  • Deliver, support, and enhance M365 services in Exchange Online, Exchange Online Protection, retention policies, litigation holds, etc
  • Introduce new and modify existing M365 mail flow features and services across NASA and support customer issues

Required Technical Skills

• Advanced proficiency in Red Hat Enterprise Linux (RHEL 8/9) Bash administration.
• Advanced proficiency in Hybrid Exchange and the M365 collaboration stack
• Expertise in Postfix SMTP configuration, troubleshooting, and mailflow
• Expertise in SPF, DKIM, DMARC implementation, troubleshooting, and monitoring.
• Familiarity with load balancers (NGINX, HAProxy) and reverse proxy setups.
• Solid understanding of DNS, TCP/IP, LDAP, and secure email transport (TLS/SSL).
• Scripting skills in Bash or Python and PowerShell.
• Experience with automation tools (Ansible, Puppet).
• Knowledge of system monitoring tools and performance tuning.

Qualifications

• Must be able to obtain a Public Trust or currently possess a security clearance to be considered
• Bachelor's degree in Computer Science, Information Technology, or equivalent experience.
• 8-12 years of relevant experience
• Experience with SMTP management including configuration, security, and troubleshooting
• Hands-on experience in command-line Linux system administration
• Experience as service owner within an enterprise C M365 environment
• Red Hat certifications (RHCSA, RHCE) strongly preferred.

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo - because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 - and moving faster than anyone else dares.

Original Posting:
January 29, 2026

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

Pay Range:
Pay Range $92,300.00 - $166,850.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.