Senior Systems Engineer - Email Deliverability & Infrastructure

We are seeking a highly technical, impact-driven Senior Systems Engineer to own, scale, and protect our core email transmission infrastructure. In this role, your golden rule will be Reputation Above All.

You are not just managing email lists or monitoring dashboards; you will architect and maintain the high-availability server infrastructure, Mail Transfer Agents (MTAs), and automated defensive systems that ensure our legitimate traffic hits the inbox while bad actors are ruthlessly contained.

The idóneo candidate bridges the gap between deep Linux systems administration, network engineering, and advanced email deliverability strategy. You will have a massive impact on the company by safeguarding our global IP/domain reputation, minimizing blast radiuses, and ensuring zero-downtime mail operations across our entire infrastructure network.

- Location: Fully Remote (Global)
- Compensation: $24k to $36k USD Yearly
- Position Type: Full-Time Contract

Role Overview

We are seeking a highly technical, impact-driven Senior Systems Engineer to own, scale, and protect our core email transmission infrastructure. In this role, your golden rule will be Reputation Above All. You are not just managing email lists or monitoring dashboards; you will architect and maintain the high-availability server infrastructure, Mail Transfer Agents (MTAs), and automated defensive systems that ensure our legitimate traffic hits the inbox while bad actors are ruthlessly contained.

The ideal candidate bridges the gap between deep Linux systems administration, network engineering, and advanced email deliverability strategy. You will have a massive impact on the company by safeguarding our global IP/domain reputation, minimizing blast radiuses, and ensuring zero-downtime mail operations across our entire infrastructure network.

Core Responsibilities

1. Infrastructure Management & High Availability

- MTA Optimization: Maintain and configure core MTAs (Postfix, Postal) and IMAP/POP3 servers (Dovecot), ensuring graceful reloads over restarts to prevent dropping active connections.
- Traffic Routing & Load Balancing: Utilize HAProxy and network routing protocols (like BGP via FRRouting) to distribute outbound traffic and architect high-volume failover mechanisms.
- Redundancy & Failover: Administer backend infrastructure databases (PostgreSQL replica setups) and maintain dedicated "Block" backup/archive servers to instantly take over the workload of a failed primary "Cube" server.
- Architectural Segregation: Maintain strict workload isolation across our infrastructure network—separating standard nodes for mail stacks, specialized injection nodes (Postal), and separate archiving/backup systems to prevent high-volume senders from degrading performance.

2. Deliverability Engine & Authentication Protocol Architecture

- Protocol Enforcement: Act as the absolute technical authority on DNS and authentication setups, maintaining flawless configurations for SPF (navigating the 10-lookup limit), DKIM (key rotation and forwarding protection), DMARC (safely driving policies toward p=reject), and BIMI.
- Traffic Throttling: Implement automated, MTA-level dynamic throttling to handle 4xx deferrals instantly, preventing a single high-volume sender from triggering global rate limits across our shared IP pools.
- Warm-up Strategy: Design and guide automated IP/Domain Warm-up Plans for new infrastructure, managing incremental volume scaling over 2–4 week cycles.

3. Edge Security, Anti-Abuse & Incident Response

- Outbound Spam Filtering: Configure and optimize Rspamd to actively scan, flag, and quarantine highly spammy content before it exits our network.
- Edge Defense: Deploy automated connection-dropping systems (Fail2Ban, custom SMTP blocker scripts)



to mitigate authenticated attacks, brute-force attempts, and malicious traffic.
- Blast Radius Mitigation: Program and maintain a dynamic IP pooling engine ("The Penalty Box") to instantly isolate accounts displaying poor metrics (bounces, FBL spikes) away from prime Tier-1 IP pools.
- Blocklist Remediation: Act as the primary responder to major DNSBL (e.g., Spamhaus) listings. Leverage log analysis to locate the root cause account, plug the security leak, and submit expert delisting requests.

4. Observability & Monitoring

- Log Shipping Architecture: Build and manage high-performance log aggregation pipelines using Vector to ship system and MTA data into a centralized repository for real-time auditing and incident response.
- Network Auditing: Utilize IPAudit and custom tools to continuously scan for bandwidth anomalies, connection spikes, or compromised user credentials.
- Dashboard Management: Actively monitor ISP infrastructure portals daily (Google Postmaster Tools, Microsoft SNDS, Yahoo Sender Hub) along with third-party tracking tools (GlockApps, Validity/ReturnPath, MXToolbox, DMARCian).

Requirements

Must-Have Technical Stack & Skills

- Systems Engineering Background: 5+ years of experience as a Linux Systems Administrator, DevOps, or Infrastructure Engineer with deep networking knowledge (TCP/IP, routing, ports, DNS management).
- MTA Mastery: Expert-level proficiency configuring, debugging, and optimizing enterprise mail tools such as Postfix, Dovecot, or Postal.
- Security & Filtering: Hands-on experience writing rules and maintaining mail-filtering/anti-abuse applications like Rspamd and Fail2Ban.
- Observability Pipelines: Proven experience building or maintaining log pipelines using Vector or similar high-scale telemetry frameworks.
- Infrastructure Automation: Experience implementing network routing layer tools (HAProxy, FRRouting) and relational databases (PostgreSQL replication).
- Certificate Management: Strong familiarity with automated SSL/TLS certificate rotation and multi-node compliance monitoring to ensure broken TLS never causes silent drops.

Deliverability & Operational Standards

- Deep comprehension of the difference between Delivery (server handoff) and Deliverability (inbox placement).
- Expert parsing of aggregate DMARC reports using platforms like DMARCian, Valimail, or Postmark.
- Strict commitment to Acceptable Use Policies (AUP): zero tolerance for purchased/scraped lists and a firm grasp on Feedback Loop (FBL) automated triage.

Key Performance Indicators (KPIs)

Your success in this role will be directly measured by your ability to keep our infrastructure metrics pristine:

- Global Infrastructure Spam Complaint Rate: Maintained strictly under 0.1%.
- Global Hard Bounce Rate: Kept consistently below 2.0%.
- Infrastructure Uptime: 99.99% availability across all outbound MTAs and mail relays.
- Incident Isolation Time: Transitioning high-risk or abusive senders to the "Penalty Box" or circuit-breaking campaigns within minutes of a threshold breach.

Benefits

This is a highly technical systems engineering role, not a marketing or email campaign management position. To be considered, you must have hands‑on experience configuring Linux mail servers at the command-line level.

About Abbott

Abbott is a global healthcare leader that creates breakthrough science to improve people's health. We are always looking toward the future,



anticipating changes in medical science and technology.

Working at Abbott

At Abbott, you can do meaningful work, grow and learn, care for yourself and your family, be your true self, and live a full life. You will have access to:

- Career development with an international company where you can grow the career you dream of.
- A company recognized as a great place to work in dozens of countries around the world and named one of the world’s most admired companies by Fortune.
- A company recognized as one of the best large companies to work for, as well as a best workplace for diversity, working mothers, female executives, and scientists.

The Opportunity

This position is based at our pharmaceutical manufacturing plant located in Florencio Varela, Buenos Aires.

As an IT Infrastructure Specialist, you will be responsible for systems administration, including level‑2 support. Analyzes and designs divisional systems. Installs, tests and upgrades systems. Participates in technical disaster recovery plan testing. Assists in system security planning. Provides technical problem isolation and resolution for a Network (LAN / Wireless / Physical infrastructure) and may refer to documented processes as needed. This includes isolating cable issues, performing diagnostics, and configuring network devices.

Core Job Responsibilities

Provides level‑2 support, including incident handling, problem resolution, and Break/Fix. Provides hardware maintenance and software maintenance (operating system, system utilities, security tools, monitoring tools, tuning tools). Provides change management support including installation qualification, operational qualification, and configuration management. Provides development and maintenance of system documentation (technical, operations, support and user). Provides system tuning, and capacity planning and management. Manages problem resolution: Reviews customer needs, gathers information from relevant sources to understand problems; and identifies irregularities before major problems occur. Documents call data into a tracking system.

Responsible for creating, updating and completing documentation associated with qualification, incident handling, problem resolution and asset tracking. Clearly and concisely provides relevant information with the audience in mind. Maintains a comprehensive knowledge of new technologies equipment and services in the data communications industry. Participates in disaster recovery planning and testing for infrastructure and client business applications. Installs, tests and upgrades platform, common, or shared systems including hardware, operating systems and associated infrastructure software (system utilities, security tools, monitoring tools, tuning tools, etc.) for both new and existing systems. Participates in analysis and design of division, common, or shared systems including hardware, operating systems and infrastructure software (system utilities, security tools, monitoring tools, tuning tools, etc.) for both new and existing systems. Tests, and implements system security for operating systems, infrastructure software (system utilities, security tools, monitoring tools, tuning tools, etc.) and infrastructure devices. Assists other BTS lines of business with their site operations as necessary.

Required Qualifications

- Bachelor's Degree, or technical institute degree in Computer Science, Information Systems, or other related field. Or equivalent work experience.
- 3 to 4 years of IT work experience in computer systems or support with demonstrated working knowledge of basic hardware and software products and problem solving/troubleshooting skills.

An Equal Opportunity Employer

Abbot welcomes and encourages diversity in our workforce.

We provide reasonable accommodation to qualified individuals with disabilities.

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