Module Webform won't send email to certain address For some reason the normal contact form won't work. It doesn't send any mail to any address I request. 
Therefore, I used the module Webform for Drupal 7.

The problem I have is almost the same described in this thread.  

However, for me the problem is even when the domain name is the same.  Like user1@domain.com works, but info@domain.com doesn't.

When I do send to a gmail account, there also is no problem.
Basically, the info@domain.com doesn't seem to be 'supported'.
All the other email addresses do work.

The domain-email is hosted by Gmail. (A Google Business account)

What am I missing?
I was having this same issue. I contacted my host (Hostmonster) and found that there is a setting in your Zone Editor that can fix this issue. 

Under MX (Mail Exchanger) I selected Remote Mail Exchanger and under the section that says "Points to" I put exchange.domain.com (replace domain with your domain name). I did this because we are running all of our email through an exchange server.

Try calling your host and explaining the problem.

I hope this helps!