Senior Systems Administration

This position requires office presence of a minimum of 5 days per week and is only located in the location(s) posted. No relocation is offered.

Join AT&T and help shape the future of communications and technology that connect the world. We value innovators who seek to explore the unknown and challenge the status quo. Bring your bold ideas and fearless spirit to redefine connectivity and transform how people share stories and experiences. At AT&T, you won’t just imagine the future—you’ll build it.

What you’ll do:
• Monitoring, Troubleshooting, and Service Availability: Ensure continual service availability through monitoring, troubleshooting, and analyzing problems to prevent service disruptions and to identify root causes along with mitigations to prevent future occurrences.
• Security management, compliance, and data integrity: Perform security compliance, auditing, and remediation, perform set up, maintenance, and monitoring of backups, along with routine hardware and software audits to ensure configuration and standards compliance.
• DevOps and Standards: Develop, promote, and curate standard operating/method of procedures in conjunction with risk assessments to reduce hazards to the network and new solutions being developed, while also maintaining and continuously improving tools, ad-hoc scripting, and automation infrastructure for configuration management, maintenance, testing, auditing, problem remediation and capacity planning.
• Vendor Management: Collaborate with and manage vendors to drive defect resolution and enhancements for internal customers to meet departmental or enterprise business needs, in addition to providing extended support as required.
• Software Installation, Upgrades, and Readiness Testing: Perform and schedule software installations and upgrades to operating systems and layered software packages and may also perform Operational Readiness Testing and Operational Acceptance Testing.

What you’ll need:

Ensure continual service availability by proactively monitoring, analyzing, and resolving issues in production on-premises cloud infrastructure which will require working with teams such as architecture, labs, other operations support teams, and cloud tenants to maintain maximum stability, performance, and security of the current and future cloud environments via the DevOps model while utilizing subject matter expertise in at least some of the following: Linux, cloud computing, Kubernetes, Open.

What you’ll bring:

The Senior System Administrator is responsible for the design, implementation, operation, and optimization of enterprise email transport systems. This role provides advanced technical support for Linux-based messaging environments, including Sendmail/Postfix MTAs and associated SMTP infrastructure, ensuring reliable, secure, and scalable email delivery across the organization.

The position requires deep expertise in Linux system administration, email protocols, and enterprise messaging architecture, with a strong focus on operational excellence, security, and automation.

Email Infrastructure & Operations

• Administer and support enterprise email transport systems, including Sendmail and/or Postfix mail transfer agents (MTAs)

• Monitor and manage inbound and outbound email traffic across corporate relay systems

• Maintain and troubleshoot SMTP mail queues, including resolving latency, backlogs, and mail storms

• Manage enterprise SMTP routing, relay configurations, and mail flow policies

• Support SMTP, ESMTP, and related protocols, including secure mail transport via TLS

• Maintain DNS configurations relevant to email delivery (MX records, routing dependencies)

System Administration (Linux/Unix)

• Install, configure, and maintain Linux-based servers supporting email infrastructure

• Perform system provisioning, patching, upgrades, and decommissioning activities

• Ensure high availability and performance of production systems

• Troubleshoot OS-level and service-level issues impacting messaging platforms

Security & Compliance

• Implement and manage anti-spam, anti-virus, and content filtering controls

• Ensure secure email transport through TLS encryption and certificate management

• Enforce enterprise email policies and content control utilizing ProofPoint Services

• Collaborate with security teams to mitigate vulnerabilities and ensure compliance

Automation & Scripting

• Develop and maintain automation scripts using Bash, Perl, or similar tools

• Automate operational tasks such as monitoring, lo