KMail is the email component of Kontact, the integrated personal information manager from KDE. Developed by KDE
License: Open Source
KMail is a comprehensive open-source email client that excels in security and integration with other productivity tools, while Polymail focuses on enhancing productivity through advanced tracking and collaboration features. Users looking for a secure, integrated solution may prefer KMail, while those needing modern email management and tracking capabilities might find Polymail more suitable.