If you’ve worked on a digital product, whether as a developer, product manager, or business leader, you know that the most common problems in software development are rarely as straightforward as “bugs.” Troubleshooting through trial and error is a crucial skill for developers to find solutions to complex issues. Courier's Gmail integration and API rate limits can cause 429 errors when sending bulk transactional emails, requiring developers to use Google-fu to troubleshoot. An incomplete data profile can also cause issues, such as "unroutable" / "MISSING_PROVIDER_SUPPORT" errors in the response, which can be fixed by adding an email recipient to the profile. Courier's Inbox and Toast features require a more detailed profile in the request, but exceptions exist for certain providers like PagerDuty. In some cases, notifications may not persist due to a subtle oversight, such as missing `to.user_id` or `to.courier.channel` in the SEND request. The team at Courier is constantly working on improving and fixing bugs, and provides support options through their documentation and 1-1 with engineers and support staff.