• The White House used Lotus Notes until 2002 or 2003
• The White House currently uses Outlook
• Mr. Rove and others also make heavy use of BlackBerry handheld devices

At this point, we don't explicitly know what server technology was used, although we think it's fair to make a working assumption that the Executive Office of the President used Lotus Domino until 2002 or 2003 and, most likely, Microsoft Exchange since then.

Question: What exact server technology is the Executive Office of the President using?

Further, it's reasonable to assume that the BlackBerrys in use by Mr. Rove and others most likely run through BlackBerry Enterprise Server. However, it's also important to realize that BlackBerrys are also available from ISPs, phone companies, and even AOL, so we can't be sure Rove's BlackBerry email is traveling through an EOP-controlled server.

Question: What service is being used to transmit Mr. Rove's BlackBerry communications?

We also don't know how Mr. Rove splits up his EOP-related BlackBerry communication and his RNC-related BlackBerry communication.

Question: Does Mr. Rove use more than one BlackBerry?

Further, we can't really know what server technologies are being provided by the RNC (Republican National Committee) for Mr. Rove's GWB43.COM account. This is very important, because if he's using an Exchange server or even IMAP (Internet Message Access Protocol), his saved message would reside, at least for a while, on the server.

However, if he downloads his messages from the server via POP3 protocol to his local machine, his saved messages would reside solely on his local machine, in the .PST files we've discussed so often.

Question: What protocol is used for Mr. Rove's GWB43.COM email access?

Finally, if he has other accounts beyond EOP.GOV and GWB43.COM, the same questions need to be asked. For example, if he has a Gmail account, much of that information is likely to be logged by Google and may be available as a result of a subpoena.

The next phase of our investigation
This is a huge story. Next week, we'll look at the question of who runs GWB43.COM, links from Karl Rove's email to Newt Gingrich, the Ohio GOP, and the strange question of whether Ohio's election results were run through a 12-person ISP in Chattanooga, Tennessee.

Later, we'll talk about issues of the White House's migration from Lotus Notes to Outlook during wartime, what happened to the missing emails (and whether they're even missing), how to search for external records if everything's been deleted, and, finally, what might be the surprisingly low tech (and low reliability) way the White House may be preserving its email records.

Contributing Editor Bill Mann is a freelance technology writer/instructor who has trained over 2000 people in the use of Microsoft Outlook. Check out his book, "How to Do Everything with Microsoft Office Outlook 2007" on Amazon.com. For more on Outlook, visit his website at http://www.living-with-outlook.com. You can also write him at Outlook2007@techforyou.com.