To export emails from Outlook to Outlook Express, you'll need to follow a few steps since these applications don’t share a direct export/import feature.

1. Convert Outlook Emails to a Compatible Format: Start by exporting your Outlook emails to a .PST file. Open Outlook, go to File > Open & Export > Import/Export, and choose Export to a file. Select Outlook Data File (.pst) and save it to your computer.
2. Convert .PST to .EML Format: Outlook Express requires emails in the .EML format. To convert, you can use a third-party tool like an Outlook email extractor, which can extract emails from a .PST file and save them as .EML files. Some extractor tools also allow batch export to streamline the process.
3. Import .EML Files to Outlook Express: After conversion, open Outlook Express and simply drag the .EML files from the folder where you saved them into your Outlook Express inbox.

Using an Outlook email extractor makes it easier to handle bulk emails during this process and helps avoid data loss during the format conversion.