No! Well, yes: just 1.

In fact, we support many customers that have only 1 mailbox. You'll need to have at least one mailbox for your domain administrator, to control your configuration and settings, and to receive mail. Remember also that mailbox aliases and distribution lists are unlimited and free-of-charge, so you can have sales, info, accounting and other names all aliased to 1 main mailbox, or even mapped to external addresses of contractors and other resources, so they can efficiently receive mail from your domain, too.

You are given the ability to add up to 99 more mailboxes upon activation, a few minutes after we accept your order securely online. If you need more than a total of 99 mailboxes, make a request at our online help desk, and they will raise your quota for mailboxes well above your current needs. We have many customers with hundreds of mailboxes, and virtually unlimited quotas to add more as needed. There's no maximum, if you need them, we'll make more available to you!