The Import/Export option in Outlook may be greyed out for several reasons. It often happens if you're using a restricted work or school account, Outlook is running in a limited mode, or your administrator has disabled the feature through Group Policy. In some cases, a damaged Outlook profile or unsupported account type can also cause this issue.

To fix it, try these steps:

Restart Outlook and your computer.
Run Outlook as an administrator.
Create a new Outlook profile.
Check whether you're using a Microsoft Exchange or Microsoft 365 account with restricted permissions.
Update Outlook to the latest version.

If you only need to access or convert a PST file and can't use Outlook's Import/Export feature, you can use Advik PST Converter. It lets you open and convert PST files without relying on Outlook's Import/Export option and supports exporting emails to PDF, EML, MSG, MBOX, Office 365, Gmail, and many other formats.

Learn More: https://www.adviksoft.com/blog/solve-import-export-option-greyed-out-outlook-2016-2013-error/