Here is an easy and free way to convert your archived Microsoft Outlook emails into a more standard and searchable mbox format. The mbox format files will be plain text, and will be much smaller than the binary .pst files, and even smaller when zipped up.
Here is the procedure:
1. Install Mozilla Thunderbird, Portable Edition. Set up an email account, using Local Folders.
2. Start Microsoft Outlook, and open your .pst files that contain your archived emails.
3. Import your emails into Thunderbird, using Import on the Tools menu.
4. After the import is complete, you will see a new Local Folder called Outlook Mail. Create a new folder under Local Folders, and move email messages into that.
5. You may delete the Outlook Mail folder after all the emails have been moved out.
6. Exit Thunderbird and Microsoft Outlook.
7. Navigate to the Thunderbird's email directory, which would typically be C:\PortableApps\ThunderbirdPortable\Data\profile\Mail\Local Folders. Find a file with the same name as the email folder that you created. Ignore any files with a .msf extension. This file is in the mbox format. Move out the email file into your backup directory, and preserve it carefully. You may zip it up, and burn it to a CD.
To read or search through your old emails, which are in the mbox format,
1. Make sure that Tunderbird is not running.
2. Copy your archived emails in the mbox format into the Thunderbird Local Folders directory, typically C:\PortableApps\ThunderbirdPortable\Data\profile\Mail\Local Folders. 3. Start Thunderbird, and search and read your old emails.
The above procedures will work best with Mozilla Thunderbird, Portable Edition, but will work with plain old Mozilla Thunderbird too, if you know where to find the Local Folders for email.