Background / Problem
We created a new sender address to improve campaign segmentation and deliverability tracking.
However, because this was a brand-new sender domain, it initially had no reputation with mailbox providers — posing a high risk of emails landing in spam folders or being throttled.
The key objective was to gradually build a positive sender reputation through a structured warm-up process before moving to full-scale email campaigns.
Actions Taken
The email warm-up was executed over three distinct phases from May to October 2025, with careful monitoring of delivery and engagement metrics:
- Phase 1 (Starting May 2025):
Initiated with a small batch of emails to verified, high-engagement recipients. Sending volume was gradually increased to signal consistent and trustworthy behavior to inbox providers.
However, a temporary pause was required after an overly rapid volume increase led to a minor reputation drop. - Phase 2 (Starting July 2025):
Once the new sender reputation stabilized at Medium, warm-up resumed with moderate sending volume. This phase faced some interruptions due to content readiness and a minor dip in reputation, prompting another short pause for system calibration. - Phase 3 (Starting August 2025):
Relaunched under a controlled and optimized schedule. The team closely monitored metrics such as delivery rate, open rate, and engagement consistency. The steady volume scaling and improved content quality successfully strengthened the sender’s domain reputation — reaching High by late October.
Results / Impact
| Metric | Performance |
|---|---|
| Total Emails Sent | 183,057 |
| Delivery Rate | 92.76% |
| Open Rate | 28.88% |
| Click-Through Rate | 0.41% |
| Final Domain Reputation | High |
- Successfully built a trusted sender reputation from scratch.
- Deliverability stabilized above 90%, confirming strong inbox placement.
- Engagement signals (open and click rates) validated sender authenticity.
- The sender address is now ready for full-scale campaign deployment with sustainable deliverability performance.
Key Takeaway:
Starting with a new sender address requires patience, data-driven control, and engagement-focused strategies.
By warming up gradually and maintaining consistent activity, the CRM team effectively established a High domain reputation, ensuring future campaigns can achieve optimal reach and performance.
