So I just noticed this issue, and it's rather urgent we find a solution, it's literally been ongoing unnoticed several days, as any communication being sent to us from our email forms and offer forms on the site are essentially going into a black hole.
We just did a change from Shared to a VPS. Have been using Google Apps Gmail all along.
Not sure if this is a misconfigured DNS or what but it's odd that every possible way of sending and receiving mail works, except when the server sends mail to emails with the @domain.com's email address.
Does anyone perhaps know what can cause this issue? Or a way to debug it? It'd be greatly appreciated!