"Editor= Owner" is not supposed to work, so that's why it is so slow -
infinitely slow I suspect :-) The first address is where the incoming
messages are sent, it must be something one can mail to. After that you
can put whatever you want. Remember, an "access level" is something that
defines who can do what, it is not necessarily a list of mailboxes. It
can contain wildcards for instance, or statements that local users or
only users on network X or country Y can have access. In the general
case, it's not something you can send mail to, and that's why the first
address has to be a plain mailbox.
Eric