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# Sr. Systems Engineer

- **Company:** Horizontal Talent
- **Location:** Washington, DC, United States
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Systems Engineering, Cyber Security, System Configuration, Message Transfer Agent, Linux System Administration, Linux Servers, IronPort, Firewall Services Module, Vmware
- **Published:** August 11, 2026
- **Apply:** https://www.disabledperson.com/jobs/74220943-sr-systems-engineer

## About the Role

* Expert-level experience designing, configuring, and maintaining Proofpoint in an enterprise environment.
 * Strong knowledge of email security operations, including firewall rules, block lists, and message quarantine/release processes.
 * Deep understanding of MTA and Proofpoint Messaging Security Gateway, including version 8.x.
 * Hands-on experience with Linux Server administration.
 * Experience supporting VMware-based environments.
 * Ability to work onsite and reside within a 50-mile driving radius of the Board offices in the greater DC metro area.
 * U.S. citizenship is required.

Preferred Skills

 * Experience supporting email security platform migrations in enterprise settings.
 * Familiarity with working through background check and drug screen processes upon offer.
 * Strong communication and collaboration skills for working with technical and business stakeholders.
 * Ability to manage priorities in a fast-moving environment where candidates are reviewed as submitted.

Horizontal is committed to fostering a diverse, equitable, and inclusive workplace where everyone feels respected, supported, and empowered to contribute. We welcome applicants from all backgrounds and experiences who are excited to help deliver secure, reliable technology services.

## Description

Join a high-impact infrastructure team supporting the migration of enterprise email security services from on-premises appliances to a cloud-based Proofpoint solution. This role offers the opportunity to help ensure a smooth transition with minimal disruption while working in an onsite environment in the greater DC metro area.
Responsibilities

 * Lead the migration from on-premises IronPort email security appliances to a cloud-based Proofpoint email security platform.
 * Design, configure, and maintain Proofpoint as an enterprise service.
 * Manage Proofpoint firewall rules and maintain block lists.
 * Respond to requests to quarantine or release email messages.
 * Support messaging security operations with a strong understanding of mail transport architecture and security gateways.
 * Work with Linux servers and VMware environments as part of ongoing platform support.
 * Collaborate with stakeholders to support a seamless transition and uninterrupted email services.


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