Opt-out is important for mailing-list-to-blog posting

[Moritz Schroeder]

... because you can invite the default unique email address of your blogger blog using Yahoo Groups, because it is opt-out, no confirmation needed.  You just delete the confirmation email blog post immediately.  Otherwise this address is really public, available and usable to every blog reader.

Google Groups asks for confirmation and the blogger email address can only receive email.  Therefore if you wanted to use Google Groups to post article on a blog, you need to create a generic email address (ie donotpublishth...@gmail.com) with automatic forwarding to the blog-email-address.