You shouldn’t need a plugin. You could be having a problem with authentication. Also, did you check to make sure the email was actually in the inbox of the address you sent to? One last thing, I’m just guessing on this, but I think that it will probably take a little while for the email to get posted. Since it’s not dependent on a cron job to run the script it will have to wait for the WP hook for email to run in order to post the message. I would think reloading the page a couple of times would work though.
I’ve seen users have trouble with this in the past because a step was missed in some way or another. Take a look at this article: http://codex.wordpress.org/Post_to_your … sing_email It’s very helpful in getting that working. Good luck! :)