samba group receives far less messages than the list

Hello,

the gmane.network.samba.general group corresponds to the
[email protected] (https://lists.samba.org/archive/samba/)

The group sometimes (once a month) receives a few emails, so it doesn't
look completely unsubscribed, but the list is much more active.

I tried to resubscribe with the admin interface, but got an error
message: Invalid list address [email protected]: Initial greeting:
(timed out while talking to server)

The address is the right one.

Can you have a look ?

Thanks,
-- 
Rémi