According to https://www.arduino.cc/en/Main/ContactUs there is a developer mailing list at https://groups.google.com/a/arduino.cc/forum/?fromgroups#!forum/developers I used to visit the developer list occasionally, but now I get an error page from Google groups:
This group is on a private domain.
Please sign in with an authorized account to view this content.
I normally use Firefox (52.0.2,Win7), I also tried IE (11,Win7).
Is there a problem with the developer list, or do I need to apply for authorization somehow?