Eudora email client now open source software
The Eudora email client - originally for Macintosh but later released for MS-DOS and Windows - was a popular email program in the 1990s and early 2000s. Qualcomm stopped development on Eudora in 2006. Now, Qualcomm and the Computer History Museum have made available the source code to the Eudora email client. Available under the 3-clause BSD license, you can download the Windows and Macintosh versions of Eudora. They don't provide the DOS version, but if an interested developer would like to port the code to FreeDOS, feel free.