POPmail was an early e-mail client written at the University of Minnesota. The original version was a Hypercard stack that acted as a post-office-protocol (POP) client. Later versions of POPmail were written as normal Macintosh applications, and a PC version of POPmail was also released. POPmail and Eudora were both instrumental in moving higher education e-mail use away from terminal-based user interfaces and into a client server/GUI metaphor. Searches of USENET news from the late 1980s-early 1990s [http://groups.google.com/groups?as_q=eudora&num=100&scoring=r&hl=en&as_epq=&as_oq=&as_eq=&as_ugroup=&as_usubject=&as_uauthors=&lr=&as_qdr=&as_drrb=b&as_mind=1&as_minm=1&as_miny=1981&as_maxd=22&as_maxm=2&as_maxy=1992&safe=off illustrate the early adoption of TCP/IP-based mail clients, and increasing popularilty of this approach in the early 1990s.