Please be advised to read their rules and/or terms & agreement!
You must use a valid email address when you decide to join because the paid email will be sent to it and to not confusing you by a lot of emails that sent I recommend you to use ONE email address only! And it is very wise to separate it with your company email or private email, I suggest you to make a new one. For your information free account from Bigfoot.com only forwarding you 30 emails each day so don't use it. Also some free email forwarder services sometime don't forward your email like Netforward.com (from my personal experience) so don't use it, use their paid account instead.
I highly recommend you to use your own email account provider (ISP) and be careful to pay your bill or you will lose your ISP email account and ofcourse it will be a disaster! Maybe you can use a reliable company like Yahoo.com but its security is far than safety because I've met onlinely a person who crack and read many FREE Yahoo email accounts and I don't know about their paid accounts security so don't ask me. Or maybe you can try BoxFrog. At last, I just want to inform you the potential problem which might be encountered in the future, that's only a probable thing though. It's all your decision to judge the uncertainty!