AWS SES Case Study: Scaling Email Delivery to 200M+ Messages Per Month

Challenge

TargetBay, a leading eCommerce marketing automation platform, needed to dramatically scale its email operations to serve a rapidly growing customer base. The platform required the ability to send over 200 million emails per month with consistently high deliverability rates.

Key challenges:

• SES Sandbox Limitations: The default sandbox environment restricted sending to verified addresses only, blocking the ability to send emails at scale
• Dedicated IP Requirements: Shared IP pools did not provide the sender reputation control needed for high-volume transactional and marketing emails
• Bounce and Complaint Tracking: No automated system for handling bounces, unsubscribes, and complaints, risking blacklisting
• Domain Authentication: SPF, DKIM, and DMARC records needed proper configuration to establish sender legitimacy
• IP Warm-Up Risk: New dedicated IPs required careful warm-up to prevent immediate blacklisting by major email providers

Solution

FactualMinds designed and implemented a comprehensive email delivery infrastructure on Amazon SES, addressing every layer from sandbox removal through ongoing reputation management.

SES Sandbox Removal and Scaling:

Facilitated the AWS approval process for production sending access, documenting sending patterns, use cases, and compliance measures to secure high-volume sending limits.

Dedicated IP Allocation and Warm-Up:

Provisioned dedicated IP addresses and designed a phased warm-up strategy that gradually increased sending volume over several weeks, building a strong sender reputation with major inbox providers before reaching full capacity.

Domain Authentication and Verification:

Configured SPF, DKIM, and DMARC records for all sending domains, establishing cryptographic proof of sender identity and enabling receiving servers to verify message authenticity.

Automated Bounce and Complaint Handling:

Built an event-driven architecture using AWS SNS and SQS to capture and process bounce notifications, complaint feedback, and unsubscribe requests in real time, automatically suppressing problematic addresses before they could damage sender reputation.

Implementation Details

Monitoring and Optimization:

Amazon CloudWatch was configured to continuously monitor SES reputation metrics including bounce rate, complaint rate, and sender score. Custom dashboards provided real-time visibility into email delivery health, with automated alerts triggered when metrics approached risk thresholds.

Ongoing Tuning:

The system was designed for continuous optimization, with regular analysis of delivery metrics to identify patterns and adjust sending strategies. This included monitoring inbox placement rates across major providers, adjusting send timing to optimize engagement, and maintaining suppression lists to prevent sends to invalid or unresponsive addresses.

Architecture Decisions:

• SNS topics for real-time event routing of bounces, complaints, and delivery notifications
• SQS queues for reliable, asynchronous processing of feedback events
• CloudWatch dashboards for operational visibility and alerting
• Phased IP warm-up schedules aligned with TargetBay’s sending calendar

Results

The Amazon SES implementation delivered the scale and reliability TargetBay needed to support its growing customer base:

• 200M+ emails per month successfully sent with production-grade infrastructure
• Improved email deliverability with higher inbox placement rates across major providers
• Enhanced compliance and sender reputation through dedicated IPs with proven warm-up history
• Seamless bounce and complaint tracking with automated suppression, significantly reducing blacklisting risks

TargetBay now operates a fully managed, scalable email delivery pipeline that grows with its platform, backed by automated monitoring and reputation management that keeps deliverability consistently high.