A UK-based travel aggregator sending 4 million emails per day — booking confirmations, price drop alerts, and itinerary updates — was experiencing average delivery times of 4.7 minutes and 18% spam placement at Yahoo and AOL. During peak booking windows, delivery times spiked to 23 minutes, causing customer support escalations and booking abandonment.
The platform shared IP infrastructure with other travel customers through a managed ESP. During peak season, other senders' volume spikes caused queue saturation. Yahoo and AOL were throttling the shared IPs due to historical complaint data from other senders in the pool. The platform had no visibility into queue depth or per-ISP delivery rates.
SolutionWe deployed a dedicated 8-IP PowerMTA environment segmented by email type: 4 IPs for time-critical booking confirmations, 2 IPs for price alerts, and 2 IPs for itinerary and administrative email. PowerMTA's per-domain throttling was tuned to Yahoo and AOL specifications, and a real-time monitoring dashboard was built from accounting log data.
Results"For a travel platform, a 4-minute booking confirmation is functionally broken. The first time a customer sees their confirmation before they've closed the booking tab was a product milestone."
— VP Engineering, Travel AggregatorTravel and hospitality email is time-sensitive in a way that most verticals are not. Dedicated IP segmentation by email type, combined with per-ISP throttle tuning, eliminates queue saturation during peak periods.
