Email posting from non users

I asked this in another section 3 days ago but didn’t get a response so I am trying here, I hope that doesn’t break any rules about double posting.

I am setting up a community blog and would like to allow posts to be emailed by both registered and non-registered users. I am looking for several options in handling these posts.
1. Ability to have emailed posts by non-registered users held for moderation much like comment moderation with similar options such as blacklist words, bulk deletes and approvals.
2. Allow use of user names as categories.
3. Auto approval for registered/approved users.

Are there any plugins available that can handle something like this or can I make any changes to make it work?