Hello Guys! I’ve had the same issue with my donation page. After submit the contact form, a message informed me that the email was sent, but after checking my mailbox several times, I was still unable to receive it.
After extended searching I found the solution and it was simple. Don’t use GMail (@gmail.com), neither mailboxes handled by any other provider who uses “Sender Policy Framework” (SPF) check, as GMail does. It has been reported that even AOL, Yahoo and Hotmail use SPF.
This problem is nearly always related to the anti-spam policy of your provider who handle the mailbox where you aspect to receive the submissions. So, the best way to avoid the problem is to change your email address. Now, it works!
I hope it will help for your successful fundraising.