There are a couple of places in your account to see what your current subscription is. Probably the easiest is to click on the Settings icon in the top right corner. You'll see a menu and at the top, highlighted in blue, is your current plan.
We'll tell you if you're using the Free, Basic or Pro plan and how many email addresses you can mail to.
Or, click on your email address in the top right and select Payments option to see your current plan, any charges in your account and an option to upgrade if you need to.