If you have a CGAL related question you can post it on Stackoverflow, using the CGAL hashtag.
This mailing list is a discussion forum for users to communicate with other CGAL users and CGAL developers. The language is English. The traffic is about 5-10 mails a day on average, and the list gathers around 1250 subscribers. Moreover, please pay attention to not abuse messages with large attachements (there is a hard limit of 500KB).
This is the mailing list to which announcements related to CGAL are posted (new releases, events, etc.). This list is moderated to keep the traffic low (a few mails a year).
If you need to contact us directly because you really consider the topic not appropriate for the public user mailing list, you can send us a mail directly. Please do not use this address for technical questions, use the cgal-discuss mailing list instead in this case.