I do not seem to have this one figured out, so Far the only email for a Windows machine that I have found that is easy to backup (contacts, calendar, and messages) is MS Outlook. I am not a big MS Software fan but the only version that I have found as drag and drop simple to backup, copy to new computer, etc, as Outlook, are the portable versions - specifically had luck so far with Mozzilla Thunderbird. But this is probably true with and of the portable apps, buy nature they have to portable. Please see “USB Portable Apps” under ”Software Links”.

Even with the portable, there is no one file like a *.pst file, you have to copy the entire folder to the new stick, and even then I have not tested the upgradeability of this, I only use my portable apps stick as a way of retrieving and sending mail from my POP account, I do not count on it for storage, like I do my *.PST files.