Not Receiving Form Submission Notifications

Hello,
I have been using Gravity forms quite successfully (without any issues) for about the last 8 month on 5 websites and only recently 1 of the website is not sending me a notification when I receive a form submission. I recently upgraded to a developer licence thinking this was the issue but I am still not receiving notifications when a form is filled. The submitted form is being captured within the form entry section but I am not being notified by email. The website is and form in question is:

http://dental-insurancequotes.ca/dental-insurance-quote

Any suggestions?
Thanks

Thanks for the quick reply, I have tried the SMTP plugin without success. I have 5 forms one the site and 2 of the 3 are working.

I had the same thing on one of my sites all seems well then suddenly I was no longer getting notifications.

After following several threads on this topic I found my answer to the issue. None of the suggestions helped but what did is that it made me think about my other plugins. Here is what I found out.

Look for any other plugin that may be using the php mail or wp_mail function from WordPress or that may be co-opting it for its own version. Seems that one plugin I was using mail press which was handling everything after an update just started blocking the forms from properly sending.

There was a setting in that plugin that told it to use its own version of wp_mail once I turned that off it started sending the forms properly again. So lesson learned even plugins that play well together may start fighting kinda like toddlers.

Lesson nothing may have changed except you may have done your proper updates and something change in the plugins.

John Overall