Educated guesses
At this point, it's important to be clear that we don't have a lot of tangible information on the full spectrum of email clients and servers used. In fact, we probably have less evidentiary information for this article than for any other article we've published thusfar in this series.

However, speaking not entirely immodestly, we do know a bit about email and most of the educated guesses we're going to make throughout this article can be backed up by our relatively deep understanding of email usage patterns.

And that brings us back to Mr. Rove and how he uses email.

What we can't really be sure of is whether White House staffers like Mr. Rove use Outlook and BlackBerry handhelds for official government business, Republican political business, or both.

Question: Does Mr. Rove use Outlook and BlackBerry handhelds for official government business, Republican political business, or both?

We think it's a fair bet to assume that Mr. Rove uses Outlook and his BlackBerry for both, simply because switching between email clients is likely to be too confusing or disconcerting on a daily-use basis.

In an earlier article, we asked if Mr. Rove used other email accounts as well, in particular accounts like Google's Gmail and Microsoft's Hotmail. Because we don't have access to any confirmed answers and because we've found no evidence -- or even wild-eyed blog claims -- of Web-based email usage, we're going to ignore that possible aspect of his email usage unless something new surfaces.

Instead, we're going to look at sending a message from Outlook, getting a message into Outlook, and doing the same with a BlackBerry.

We also have no specific mention of Microsoft Exchange as an email server for either the RNC or EOP. But we think it's a reasonable probability, given Mr. Rove's active use of the BlackBerry handheld email client. Here's why.

Generally, there are two basic email management paradigms: email messages live on the server and email messages get downloaded to the client. Once you download email messages to a client, usually through the POP3 protocol, your messages exist solely on the client and can't be easily shared among machines.

If you're using a BlackBerry, however, it's unlikely you'll want to download all your email messages just to the BlackBerry. It's far more likely you'll want to keep your email messages on the server so you can reference them from any client you use, whether your BlackBerry or your Outlook client on your desktop or laptop computer.

Understanding the BlackBerry component
To get a better understanding of where the BlackBerry handheld fits in, we decided to bring in an expert. We had the opportunity to get some security information from Gary Morse, president of Razorpoint Security. Gary is a professional "white hat" hacker who specializes in network security.

Gary has more than 20 years experience in information technology, focusing on security, network architecture and new media. In particular, he is an expert in attack/penetration testing, which uncovers and identifies vulnerabilities used by hackers against corporate networks. Gary's been interviewed by CNN, CNBC, the New York Times, Forbes, Court TV, and other well-respected media outlets and he's our "go to guy" for BlackBerry security info. What follows is a short Q&A.