It will just function as an alias for all that group members. Yahoo won't save the email on their servers; instead, expands the blah@yahogroups.com to every mem

It will just function as an alias for all that group members. Yahoo won't save the email on their servers; instead, expands the blah@yahogroups.com to every member, and sends them a copy. That way, they don't need to maintain any infrastructure besides email server.