How an E-commerce Brand Cut Bounce Rate by 62%
A growing e-commerce brand used MailTester bulk verification to clean a 250k-address list before Black Friday, cutting hard bounces by 62% and protecting sender reputation.
## How an E-commerce Brand Cut Bounce Rate by 62% *Industry: E-commerce* A growing e-commerce brand used MailTester bulk verification to clean a 250k-address list before Black Friday, cutting hard bounces by 62% and protecting sender reputation. ### The challenge With Black Friday approaching, the marketing team planned the biggest campaign in the company's history to a 250,000-address list. But the list had been built over four years from signups, checkout and a handful of imports, and hadn't been cleaned in over a year. Early test sends showed a bounce rate above 9% — high enough to risk landing the entire promotion in spam at exactly the wrong moment. ### The approach The team uploaded the full list to MailTester's bulk verification, which processed it in the background and returned each address bucketed as valid, risky, catch-all or invalid. They suppressed every invalid address, moved catch-all and risky results into a low-priority re-engagement segment, and kept the clean, deliverable segment for the main campaign. Going forward, new signups are verified in real time at checkout so the list stays clean. ### The results - **Hard bounces reduced by 62% on the first post-clean send** - **Inbox placement improved, lifting Black Friday revenue per email by 18%** - **Complaint rate fell below 0.1%, protecting long-term sender reputation** > “We were about to torch our reputation right before our biggest sale. Cleaning the list first paid for itself many times over.” > > — Head of CRM, direct-to-consumer retail brand ### Get the same result Every one of these outcomes came from the same foundation: verifying email addresses before sending. You can [check an address free](/), automate it with the [MailTester API](/api), or read the [email deliverability guide](/email-deliverability-guide) to plan your own clean-up. Explore more results in our [case studies](/case-studies).