L&T Technology Services: Transforming Enterprise Email Infrastructure with Amazon SES

L&T Technology Services (LTTS) is a global leader in Engineering and R&D (ER&D) services, headquartered in Vadodara, India. Operating across 108 innovation centers worldwide, LTTS partners with global enterprises to drive digital transformation across industries including automotive, industrial IoT, healthcare, aerospace, and smart manufacturing. With over 719 patents filed for 57 of the Global Top 100 ER&D spenders, LTTS continues to redefine innovation with breakthroughs such as the world’s first Autonomous Welding Robot, the Solar Connectivity Drone, and the Smartest Campus in the World.

The Challenge LTTS managed a hybrid email infrastructure comprising Cisco On-Port for on-premise email and SMTP2GO for cloud-based applications, supporting over 250 applications and processing 150,000+ emails daily. This fragmented setup introduced multiple challenges:

• Scalability & Performance Limitations – Inconsistent throughput and high latency during peak operations.
• Security & Compliance Risks – Lack of unified authentication, encryption, and audit mechanisms.
• Monitoring & Deliverability Gaps – No centralized visibility into delivery success, bounce rates, or reputation scores.
• Operational Overhead – Manual processes for credential rotation and bounce management increased workload and costs.

The system’s inefficiencies risked business continuity and degraded user experience across critical communication systems.

The Solution LTTS partnered with AWS to modernize and centralize its email infrastructure through Amazon Simple Email Service (SES), implementing a scalable, secure, and cost-effective architecture. Phase 1: Assessment & Architecture Design

• Conducted detailed analysis of existing infrastructure.
• Designed a scalable SES-based architecture with failover capabilities.
• Deployed a Proof of Concept (PoC) to validate integration, performance, and deliverability.

 Phase 2: Pilot Implementation

• Migrated critical applications using SES Configuration Sets for granular control.
• Integrated Amazon CloudWatch for observability and Virtual Deliverability Manager to track key email metrics.

 Phase 3: Full-Scale Migration

• Completed migration of all 250+ applications.
• Integrated AWS Secrets Manager for secure credential management and automated rotation.
• Developed a custom Mail Manager to meet unique application-level constraints.

Technical Innovations The new architecture leveraged the power of multiple AWS services for automation, monitoring, and resilience: 

• Amazon SES – Core email sending, deliverability optimization, and DKIM/SPF configuration.
• AWS Lambda – Automated handling of events such as bounces and complaints.
• Amazon CloudWatch – Real-time monitoring and alert dashboards.
• Amazon SNS – Instant alerting and operational notifications.

Key Implementation Highlights 

• Suppression List Automation – Introduced a 30-minute delay for new user provisioning to allow DNS propagation, reducing bounce rates by 85%.

 

• Strengthened Security –
  • Enforced a Restrict From Address policy for strict sender identity validation.
  • Implemented automated credential rotation via Secrets Manager to eliminate manual errors.

 

• Custom Mail Manager – Enabled:
  • Flexible authentication methods
  • IP-based access restrictions
  • Real-time monitoring and custom password management

The Results Operational Efficiency

• 60% reduction in infrastructure management overhead
• 75% decrease in manual intervention
• Maintained 98%+ email delivery success rate

 Cost Optimization

• Eliminated redundant third-party providers
• Streamlined infrastructure and reduced maintenance costs
• Achieved 40% savings in total email-related operational expenditure

 Performance Improvements

• 35% faster email delivery times
• Bounce rate reduced from 5% to under 1%
• Enhanced tracking, reporting, and visibility across the email ecosystem