Exporting a massive mailbox into a single text-based format can result in very large files that are difficult to open with standard text editors like Notepad.

To download everything, go to Settings > General > Privacy and data in the web version of Outlook and click Export mailbox . Microsoft will then prepare a link for you to download your entire data history.

space in their online inbox by moving data to a hard drive. Process data for other applications, such as a database. How to Create or Download Your Own

You can also drag emails directly from Outlook to your desktop to create .eml or .msg files, which can then be converted to text if needed. Common Issues with .txt Exports