First verify that your email server is working correctly and receiving emails from other addresses. This may be an issue if you're using your own email server or one provided by your website host. There may be some delay from the time you set up your address and the time it starts to successfully receive emails.
Also, remember looking at the spam folder, if you have one. Sometimes Formspree emails may get in there.
If you are sure your email is working correctly, you can submit your form again (not using AJAX) and it will show a link to "Resend confirmation" (if the link doesn't appear on the first time, please submit the form a second time to see it). That link you will know if there is a block on your email address and remove that block for you.