This issue only affects yahoo.com email addresses. To understand why, we need to explain the notifcation from your site.

1. Let's say we have a new person and she has a yahoo.com email address.
2. She submits the form on your site including her email address.
3. Your website says, "great we have a new submission we need to tell the site administrator"
4. To keep things easy for you we setup the form to send you an email that says it is from your new person using her email address for the "Reply to:"
5. That way if you reply to the notifcation from your website, the new person gets the message.
6. In 2014 yahoo implemented a new DMARC policy stating that any message coming from a yahoo.com email address had to originate at a yahoo email server or that it is spam and should be rejected.
7. Your gmail account is seeing this DMARC policy and rejecting the notification because we said it is coming from a yahoo.com email address. In reality it is coming from your website rather than yahoo.

So, we can change the form so that the notification email comes from This email address is being protected from spambots. You need JavaScript enabled to view it.  (or any other non-yahoo.com email address that you want) OR we can leave things as they are know that you will have to be on the lookout for yahoo.com submissions. Note that if we change the form you will have to be careful to enter the address by hand if you want to reply to the new person making the submission.

I am sorry if that is all a little confusing. If so disregard the following link as it goes into DMARC further. If you are looking to address problems with insomnia and are interested in knowing more check out...

https://blog.returnpath.com/all-about-yahoos-dmarc-reject-policy/

The short version is... please let us know if you want us to change the form so that yahoo.com submissions get through but replying to the notificaiton for a new person becomes a little trickier.