I have just started using the oxwall plugin called "Contact Us" it comes as a default plugin.
When a user fills out the form and clicks submit, it gives you all the notifications to say your message has been sent. However the message doesn't end up in the specified email account inbox, it doesnt look like it gets sent anywhere.
The email side of our oxwall site works as we can email users directly and the email gets delivered within minutes.
It looks to me like the contact us plugin has a bug.