.e04 is ArcInfo export data
Key Features: .E04 File Extension
What is an .E04 file?
The e04 file extension is associated with the ArcInfo, a full-featured geographic information system for Microsoft Windows operating system.
The e04 file stores exported data.
The ArcInfo is obsolete product replaced by ArcGIS software.
This e04 file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.