Campus Mailing Lists, List rejects owner's messages

I own a list, but my messages are rejected by the list.

List owners are NOT automatically added to the subscribers list.   If an owner wants to receive and or post to a list they should also add their email address to the subscribers.  

The setting, Admin > Edit List Config > Sending/Receiving setup > Who Can Send Messages determines who can send messages to a mail list.   There are many options the privileged list owner can choose.  See Sending/receiving setup in the user doc.