The Intercom team successfully scaled their email delivery pipeline to handle a massive influx of emails triggered by the GDPR regulations on May 25th, without causing any customer impact. They achieved this through various improvements made to their scalability and resiliency efforts over time. The company's ability to stress-test their system without breaking it was put to the test during the surge, and they were able to handle tens of millions of emails sent over a 24-hour period without an increase in bounce rates. Despite the high demand, Intercom's message queue times decreased quickly as the upscaling caught up with the backlog, and the company's biggest database briefly hit a max CPU load of 32.5% during this time. The success demonstrates that Intercom has made significant progress in improving its scalability and reliability, which is crucial for supporting larger customers and bettering customer experiences.