Honestly I do not check it that much. It is Unlimited so why bother.

The last time I checked my iPhone said 1.6G used. Now I do more than just email. I surf a lot with my iPhone. My iPhone has turned into my Netbook. Infact it has replaced my Laptop on almost all my overnight trips. But yes a I get a lot of emails. I do not bother to count.

The big thing about my emails is that they all have rather large attachments with them. They are not just pithy sentences. It is more like look at this pdf or long doc. Understand that I use my iPhone as a Business device. It is my main contact for all of my business. I use it just as much as I use my iMac if not more. It is also my main business phone#. The record for Voice minutes used this year for me is over 5,000 in a single month.
I get my money's worth out of my iPhone!