Thanks for the info. I see that at least the 'Elf Clan' group has a defunct member that is set to the teen grid. I believe the notice delivery attempt to their account (which should fail) is triggering the "Unable to send IM across parent estates." message. While the message shouldn't be delivered to that user, I don't think there's any point in generating the error message to the notice sender, especially when the group has thousands of members .

Hi Eren Padar , I believe that error message implies that one of the group notice recipients is a restricted-access account that cannot access the main grid. Which SL group did you send the notice to?