From syn2cat - HackerSpace.lu
We currently have a variety of mailing lists at your disposal, the full list of which can be retrieved from our mailman.
 syn2cat's own lists
- The syn2cat-announce list is a very low traffic list whose subscribers will only receive announcements of current and future events. If you'd like to be kept informed of the latest stuff going on at the hackerspace, but don't care about organisational issues, this is the list you should subscribe to.
- The syn2cat-discuss list is our regular mailing list. This is where everybody is discussing their projects, workshops and any other ideas.
- The graffitiresearchlab is a mailing list conceived to aid in the conception and discussion of Graffiti Research Lab Luxembourg's projects and activities.
 Recommended international lists
- Hackerspaces mailing list for Belgium, the Netherlands and Luxembourg.
- International hackerspaces movement.
We use various messaging apps.
- slack https://level2lu.slack.com/ (register with your <nickname>@syn2cat.lu email adress)
- To a lesser degree: Google Hangout (just try to get an invitation from someone...)