I don't want anyone not from my domain sending email to 'everyone@mydomain.com'. Is there a way to restrict who can send mail to the group addresses? I've searched and can't find anything. Thanks in advance for any help!
Yes, there is a way to do it. Please go to the Scalix Knowledge base, click on Solutions and search for 'pdl'. You should see a topic titled "How to hide PDL from external users".