Please join those you're interested in at the following links. We recommend joining "Sakai-Users" as your first list. You'll find all our lists (as of 2017) here: https://groups.google.com/a/apereo.org/forum/#!forumsearch/Sakai
Sakai Community members are also very active in the Apereo Teaching & Learning interest group
Archives from the old email lists are at http://collab.archives.sakaiproject.org/
To contact the Sakai Community Coordinator email firstname.lastname@example.org .
To subscribe or unsubscribe to email groups
Send an email to the relevant email address by adding "+subscribe" or "+unsubscribe" to the email address. For example, sending an email to email@example.com will subscribe you to the firstname.lastname@example.org email list.
Google App Institutions
Archives of the old Collab lists are available.
Calendar of Activities
Sakai Calendar - HTML
Sakai Calendar - iCal subscription
If you can't find your "at institution.edu" on the Apereo signup page then send an email requesting access for yourself and your institution either to email@example.com or firstname.lastname@example.org .
We currently have Slack groups for Sakai developers, Sakai Morpheus (responsive design), Sakai QA and for Apereo we have Tsugi , Release engineering, uPortal, UX .