How to label GitLab notification in Gmail by headers?

Updated on 24-02-2026: Improved the script to use getHeader() instead of raw body search, added data-driven header configuration, and auto-creation of labels. 📨 How GitLab sends notifications? GitLab allows you to stay informed about what’s happening in your projects sending you the notifications via email. With enabled notifications, you can receive updates about activity in issues, merge requests or build results. All of those emails are sent from a single address which without a doubt makes it harder to do successful filtering and labeling.