Worked on enhancing email processing reliability in the Zimbra/zm-mailbox repository by addressing a parsing issue with the 'From' header. Refactored the FilterUtil.getExtendedInfo method in Java to ensure robust extraction of sender email addresses, even when headers contained extraneous characters or irregular formatting. Focused on backend development and unit testing, the work included expanding test coverage to validate both valid and malformed header scenarios, reducing the risk of regressions. These improvements increased the accuracy of sender identification, supporting more reliable email threading, filtering, and policy enforcement, while also improving code maintainability and easing future enhancements in the codebase.