KMail is described as 'The email component of Kontact, the integrated personal information manager of KDE. Kontact personal information manager and groupware software suite for KDE. It supports calendars, contacts, notes, to-do lists, news, and email' and is a Email Client in the office & productivity category. There are more than 50 alternatives to KMail for a variety of platforms, including Windows, Linux, Mac, Android and iPhone apps. The best KMail alternative is Thunderbird, which is both free and Open Source. Other great apps like KMail are Betterbird, Evolution, Microsoft Outlook and eM Client.