Senior Systems Engineer - Email Deliverability & Infrastructure

3 weeks, 1 day ago
Full-time
Senior
DevOps and Infrastructure
Mission Inbox

Mission Inbox

Mission Inbox provides an AI-powered email deliverability infrastructure designed to enhance inbox placement and facilitate email warm-up, specifically catering to cold outreach and outbound sales efforts.

Professional Services
1-10
Founded 2016

Description

  • Own, configure, and optimize core mail infrastructure including MTAs and IMAP/POP3 servers.
  • Design and maintain high-availability routing, load balancing, and failover systems across the infrastructure network.
  • Administer PostgreSQL replica setups and backup/archive servers to ensure rapid workload takeover during failures.
  • Maintain DNS and email authentication configurations for SPF, DKIM, DMARC, and BIMI.
  • Implement dynamic MTA-level throttling to handle deferrals and prevent shared-pool rate limiting.
  • Design and manage IP and domain warm-up plans for new infrastructure.
  • Configure outbound spam filtering and anti-abuse defenses at the network edge.
  • Respond to blocklist incidents by investigating root causes, remediating issues, and submitting delisting requests.
  • Build and maintain log aggregation, monitoring, and auditing pipelines for incident response and operational visibility.
  • Continuously monitor ISP portals and third-party deliverability tools for reputation and performance issues.

Requirements

  • 5+ years of experience as a Linux Systems Administrator, DevOps, or Infrastructure Engineer.
  • Deep networking knowledge, including TCP/IP, routing, ports, and DNS management.
  • Expert-level experience configuring, debugging, and optimizing Postfix, Dovecot, or Postal.
  • Hands-on experience with Rspamd and Fail2Ban or similar mail-filtering and anti-abuse tools.
  • Experience building or maintaining log pipelines with Vector or similar telemetry frameworks.
  • Experience with HAProxy, FRRouting, and PostgreSQL replication.
  • Strong familiarity with SSL/TLS certificate rotation and multi-node compliance monitoring.
  • Deep understanding of email delivery versus deliverability.
  • Experience parsing aggregate DMARC reports using tools such as DMARCian, Valimail, or Postmark.
  • Commitment to acceptable use policies, including zero tolerance for purchased or scraped lists and familiarity with FBL triage.

Benefits

  • Fully remote position with global location flexibility.
  • Full-time contract role.
  • Compensation of $40,000 to $62,000 USD per year.
  • Opportunity to work on mission-critical infrastructure with high ownership and direct impact.

Interested in this position?

Apply directly on the company website

Apply Now

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