I also had this problem. Like you I had to change the mailing list "List From Address" setting - from Poster Address to List Address.
That works for nearly all destination ISPs - apart from AOL. AOL rejects the list emails when the originating sender is an AOL address - saying:
RSP: 550 5.7.0 () Unfortunately, messages from (mail server IP address) on behalf of (aol.com) could not be delivered due to domain owner policy restrictions.
That sort of makes sense - AOL think that emails from an AOL email address should only come from an AOL server. So how do we configure a mailing list that we host so that it can handle subscribers that have an AOL email address?
Any help greatfully recieved.
Nick.