The kernelnewbies mailing list has around 1000 subscribers and around 500 email messages per month. You can subscribe to the kernelnewbies mailing list through the web interface.
The kernelnewbies mailing list is also available via Gmane and other mail2news gateways. Because of this, the mailing list is open for mailing by non-subscribers, too.
As is the case for the rest of the kernelnewbies community, anything related to kernel development is on topic. If you want to discuss something that is not related to kernel development that is fine, but please do it elsewhere.
Because the kernelnewbies mailing list has to accept email from non-subscribers, the list server employs several layers of spam blocking and filtering. The first layer consists of DNS blocklists: DSBL, SBL, CBL and PSBL. Mail servers that make it through these lists are subjected to greylisting and filtering on subject attachment types and file extensions.
After the checks at the MTA level, the mailing list software filters the mail with a number of regular expressions, as well as Spamassassin. Spamassassin does bayesian filtering, and is trained automatically:
This seems to work pretty well, since non-subscribers who post to the list tend to talk about the same things that subscribers talk about, while spam to spamtrap addresses is exactly the same spam as the spam to the mailing list.