I have been receiving emails from strangers. I think my emails address has been accidentally shown to public..

Go to the group, click edit membership along the top. In the next window scroll down and untick where it says individual email then you can tick pick up your mesages at the site, receive a daily digest or no email. Click save changes. To prevent those messenger notices: Click on messenger, top left on the messenger window then scroll down to preferences, click and scroll down to ignore list, click and in the next window tick ignore anyone not on my friend's list and click o.k.