Another one.com fan here
And yes, Dawn is correct, you can have as many emails as you want. What I really like, as well as their fantastic customer service, is that the smallest package offers everything that the bigger packages do, it's only the storage space that differs.
That's a very good point Julie, so often, the smaller packages are missing something 'important' but the one.com is more than adequate for most small businesses. Wasn't it yourself that pointed me in their direction in the first place?