Send does not work from gmail address

When sending a form, it works perfectly unless the form is sent when a user enters in an email address from gmail.com

The result is always the same from all email addresses except when from gmail, we never get the email to our address. It’s not in SPAM either. The email address receives email from gmail users all the time, but if a user enters a gmail.com email address in the from field, we receive nothing.

http://wordpress.org/plugins/visual-form-builder/