The review request form doesn't seem to be working
There are a few known issues with the review request email trigger that has the embedded form in it - it doesn't work in several email clients including iOS and Outlook b/c they basically block form submission from within an email.
I've addressed this with a new type of review request email which you can see more about here:
One-click review request
This feature is available within MageMail v2, which requires a separate account creation (more info).
You can also use a simpler version of the review request email in v1 which simply links them out to the product page to post a review instead of using the embedded form.