As a free and open-source server distributed under BSD style license, it was a common choice for Internet Service Providers, schools, corporations, and other organizations.
Qpopper was distributed by Qualcomm as source code; other parties offer pre-compiled or pre-configured versions for various platforms.
Qpopper ran on a wide variety of platforms, including virtually all Unix and Linux distribution,[1] Mac OS X, and even Windows under cygwin.
Because mbox is a linear format in which messages are stored sequentially, Qpopper supports a number of optimizations to improve speed and scalability, including a cache file to maintain mailbox state between sessions, and several optional I/O techniques.
Qualcomm's original goal was to promote the availability of correct and modern servers for the Eudora mail client to use, and also to provide a platform for newer extensions.