Linux Systems Administrator

Callidus Ltd. Corporation, a BPO for an overseas company providing a full range of business process solutions. We endeavor to execute business strategies with exceptional results and provide the best quality service and relationships with our clientele. With a strong track record of success and a commitment to excellence, we are dedicated to delivering exceptional results and contributing to the growth and success of the industries we operate in.

Overview This role supports and maintains our high-volume email infrastructure in coordination with the IT Manager. The candidate will focus on email deliverability, blacklist monitoring, and server administration to ensure smooth, uninterrupted operations of our emailing systems and related IT infrastructure.
Technical Requirements
1. Email Infrastructure & Deliverability ● Mail Transfer Agents (MTAs): Experience working with and administering MTAs like PowerMTA, Exim, Postfix, or Qmail, particularly in high-volume environments. ● Email Deliverability Best Practices: ● Strong understanding of SPF, DKIM, and DMARC setup and maintenance. ● Practical knowledge of IP warming, sender reputation management, feedback loops, and spam compliance (CAN-SPAM, GDPR considerations, etc.). ● Blacklist & Reputation Monitoring: ● Familiarity with blacklist services (Spamhaus, Barracuda, etc.). ● Ability to proactively monitor IP/domain reputation and take corrective measures to delist and prevent further issues.

2. Systems Administration ● Linux Expertise: 3+ years of hands-on experience administering Linux (preferably RedHat, CentOS, or similar). Must be comfortable with the LAMP stack (Linux, Apache, MySQL, PHP). ● WHM and Cpanel expertise. ● Networking & Security: ● Proficiency with TCP/IP, DNS, firewall configuration (e.g., iptables, firewalld), VPN management, and SSL certificate setup. ● Server Monitoring & Automation: Knowledge of server monitoring tools (Nagios, Zabbix, Grafana, etc.) and ability to automate tasks via Bash, Perl, Python or equivalent scripting languages.

3. Email Processing & Bounce Management ● Knowledge of bounce handling mechanisms and the ability to parse, categorize, and take automated action on different bounce types (soft, hard, invalid emails, etc.). ● Understanding of bounce codes and root-cause analysis for high bounce rates. ● Creating or maintaining scripts for removing unsubscribes, processing removal requests, and responding to out-of-office or human replies. ● Ability to handle or assist in VoIP administration if required (SIP, PBX, etc.).

4. Database & Data Handling ● Proficiency in MySQL administration for user management, replication, performance optimization, and data backups. ● Experience with data hygiene tasks such as cleaning and de-duplicating large email lists.

5. Scripting & Basic Programming ● Ability to write or modify scripts (Bash, Perl, Python) to automate routine tasks like data parsing, spam filtering, alert notifications, and bounce management workflows.