There is no listserv... not anymore. Peace Corps closed its daily email of jobs and housing in February 2013. For jobs, they introduced Peace Corps Career Link, and the NPCA offers its Next Step Job Finder and a housing group on its social network.
We send out a free newsletter every Wednesday morning. It lists our upcoming events, featured jobs, and items of interest to the community. Our Facebook Group serves a similar function, only it's 24/7. Our Google calendar is public and syncable too. Add our Twitter and Linkedin feeds, and you'll never miss an update.