[IMPORTANT] new mailing-list policies

[antonio.o...@gmail.com]

Hi,

due to the recent increase of Spam https://github.com/kubernetes/community/issues/7641 I've update the mailing list policy to only allow to post messages to group members.

This mailinglist has very low traffic and it has 1298 members as today, so 

I think that this is a very reasonable policy and it will avoid having people to moderate all the external posts, that most probably are all of them spam.

If you feel this is wrong please let me know.

Thanks,

Antonio Ojea