It was not, but it is now. The link is still not working.. but I see I can change the email templates via the tab Mail options.
I have tested on several test sites and it works perfectly. Besides this functionality is so basic that I understand that with the thousands of users that there are if it were a recurring problem I would have more support requests and I only see yours.
Besides, try disabling all plugins except this one and use a basic WP theme in case it is a bad interaction of other elements.
And another thing, look on the left side there should be a mail templates section.