How does the Debug Mode work?
The debug mode allows the cart to be considered abandoned as soon as any item is added to it. Normally, it would take 5-10 minutes for a cart to be considered abandoned. Therefore, it doesn't necessarily send the email right away, but rather sets an immediate starting point for a campaign timer.
Please also note that debug mode is only meant to test the process of email sending. When enabled, the debug mode will only allow sending emails to the specified domains.