One of the first electronic discussion lists devoted to teaching issues was the Edstat-l list founded at North Carolina State University. To subscribe send the message
subscribe edstat-l Your Name
to email@example.com. You may also participate through UseNet News at sci.stat.edu. Archives of Edstat-l (and several other discussion lists) are maintained by the Journal of Statistics Education Information Service.
A number of other e-mail discussion lists are maintained for specific countries (e.g. Australia, Brazil, Italy, New Zealand), statistical topics (e.g. Bayesian methods, experimental design, time series analysis), subject areas (e.g. biometry, geography, econometrics), and (many) software packages (e.g. Minitab, SPSS, SAS). An excellent resource here is Mike Fuller's List of Statistical Lists which contains information on a host of discussion lists.