Typically the biggest reason for not receiving a confirmation email is it is either being sent into an email provider's spam/clutter/promo/whatever folder, or an ISP is being helpful in not delivering it in the first place through its own attempts at curbing spam. However, I do not know why you are personally experiencing this issue. Please make sure to get in touch with Account Support here. But to answer the thread title, one purchase is all that is necessary.
I have exactly same problem, I bought the standard edition, got no mail back, no order number nothing, it did go off my bank account that is the only proof I have.
I check every folder on my email, nothing, and after 24 hours I got a reply from SSG, if you still have not got you code reply with this email and send us your order number.
I send them proof that it is off my bank account and now I sure I am going to wait another 24 hours for an answer
Typically the biggest reason for not receiving a confirmation email is it is either being sent into an email provider's spam/clutter/promo/whatever folder, or an ISP is being helpful in not delivering it in the first place through its own attempts at curbing spam. However, I do not know why you are personally experiencing this issue. Please make sure to get in touch with Account Support here. But to answer the thread title, one purchase is all that is necessary.
You really need to make the code more obvious during the purchase process. It is already displayed there after all. Just make it bigger, and give clear instructions what to do with it, and you'd get rid of all these complaints about codes and emails not being received. Think of all the time, and hence money, you'd save.