I'm trying to invite members of an existing group to join another group. It won't accept the group address

I'm using the group address (xxx@yahoogroups.com) but get a "not valid email address" error. The existing group is around 60 members. Is there a limit?
I'm trying to invite members of an existing group to join another group. It won't accept the group address
what you're attempting can tbe done. it is a valid addy, but not allowed by Yahoo's invite filters. yo can not send invites to other groups in that manner.