I have a listowner who got a rejection message “user unknown”  when trying to post to her list (she is owner). The list is set to send= private,confirm.  I looked at her list and noticed she was not subscribed. I directed her to how to subscribe, she subscribed and all was ok…except she tells me she has several other lists and is not subscribed and has had no issues sending. I checked archives and she is correct. What am I missing? I thought one has to be subscribed to send to a private list even though she owner.