How Prompt Cowboy rescued its sender reputation and cut bounce rate by ~60%
The problem
Prompt Cowboy grew fast. Hundreds of thousands of monthly active users signed up in a short window, and with that growth came a quieter problem: invalid email addresses at the signup form. Typos, disposable inboxes, and non-existent addresses piled up. Each one generated a bounce, and bounces began eroding domain reputation. Transactional emails (password resets, product updates, notifications) started missing inboxes.
"We have hundreds of thousands of MAU, and without Abstract our domain reputation was getting hammered by people typing emails wrong and undeliverable addresses. It was a real problem." — Matt Boustred, Founder, Prompt Cowboy
How they built it
Prompt Cowboy integrated Abstract's Email Validation API directly into the signup flow. Every new address is checked in real time before the account is created, so bad entries never reach the database.
What the integration covers:
- Real-time validation at the point of signup, with no lag for the user
- Disposable and throwaway address detection
- MX record and SMTP deliverability checks to catch undeliverable addresses
- Typo and format correction for common misspellings
- A single endpoint that fit into the existing signup stack
"Abstract helped us protect our domain reputation. It's the invisible layer that keeps our emails landing where they should." — Matt Boustred, Founder, Prompt Cowboy
The results
~60% drop in bounce rate. Bad addresses stopped at signup never generated bounces downstream.
Sender score recovered in weeks. Domain reputation stabilized once invalid traffic was cut off at the source.
100k+ monthly active users safely onboarded. Every new signup is verified before account creation.
What's next
Prompt Cowboy continues to route every new signup through Email Validation and is watching sender-score trends as the user base keeps growing.