Experience: 2
Employment Type: Full-time

Department: IT Infrastructure / Messaging Operations

Role Overview

We are looking for an experienced Senior Linux Administrator to manage and support our enterprise email infrastructure. The role involves ensuring the availability, performance, security and scalability of Linux-based messaging platforms.

The ideal candidate will have strong Linux administration skills, hands-on experience with email technologies and a thorough understanding of SMTP, DNS, email authentication and security.

Key Responsibilities

- Administer, monitor and troubleshoot Linux-based email infrastructure.
- Manage mail platforms and components such as Postfix, Sendmail, Exim, Dovecot, Zimbra or similar technologies.
- Maintain SMTP relays, mail gateways, queues, routing rules and high-availability configurations.
- Investigate mail-delivery failures, latency, queue buildup, spam complaints and reputation issues.
- Configure and maintain DNS records, including MX, SPF, DKIM, DMARC and reverse DNS.
- Manage anti-spam, antivirus, email-filtering and threat-protection solutions.
- Monitor server health, mail flow, storage, capacity and system performance.
- Perform Linux patching, upgrades, vulnerability remediation and security hardening.
- Develop automation scripts using Bash, Python or Ansible.
- Manage SSL/TLS certificates and enforce secure email transport.
- Perform log analysis, root-cause analysis and incident resolution.
- Plan and execute email-platform migrations, upgrades and disaster-recovery exercises.
- Maintain backups, recovery procedures, operational documentation and standard operating procedures.
- Participate in on-call support and handle critical production incidents.
- Coordinate with network, security, application and service-provider teams.
- Mentor junior administrators and contribute to infrastructure improvement initiatives.

Required Skills and Experience





- 2+ years of Linux system administration experience, preferably on RHEL, Rocky Linux, AlmaLinux, Ubuntu or CentOS.
- Robust experience managing production email or messaging infrastructure.
- In-depth knowledge of SMTP, ESMTP, IMAP, POP3, MIME and mail-routing concepts.
- Hands-on experience with Postfix, Sendmail, Exim, Dovecot, Zimbra or equivalent platforms.
- Strong understanding of DNS, MX, SPF, DKIM, DMARC and PTR records.
- Experience troubleshooting email headers, SMTP logs, delivery errors and mail queues.
- Knowledge of spam filtering, IP/domain reputation, blocklists and email-security practices.
- Experience with Linux performance monitoring, storage, networking and security hardening.
- Proficiency in Bash or Python scripting.
- Familiarity with automation and configuration-management tools such as Ansible.
- Experience with monitoring tools such as Grafana, Prometheus, Nagios, Zabbix or ELK.
- Understanding of high availability, load balancing, backup and disaster recovery.
- Strong analytical, documentation and communication skills.
- Willingness to participate in rotational on-call support.

Preferred Qualifications

- Bachelors degree in Computer Science, Information Technology or a related discipline.
- Certifications such as RHCE, RHCSA, Linux Foundation or equivalent.
- Experience with cloud-based email services or hybrid mail environments.
- Knowledge of Microsoft 365, Exchange Online, Google Workspace or email-security gateways.
- Experience with virtualized or cloud environments such as VMware, AWS or Azure.
- Familiarity with ITIL processes and enterprise incident-management tools.

Success Measures

- High availability and reliable performance of the email platform.
- Timely resolution of mail-flow and infrastructure incidents.
- Reduced spam, security events and email-delivery failures.
- Successful patching, upgrades, automation and capacity planning.
- Accurate operational documentation and compliance with security standards.

📌 Senior Linux Administrator (India)
🏢 AtoZemais.com
📍 India