The EFX file extension is used to signify fax document files created in the eFax Messenger software application. EFX files can be edited with the appropriate software.
Individual Ensoniq instrument files universal file extension.
Document created by eFax, a service that sends and receives faxes as document attachments via email; contains email attachment and email body text; can be converted into .PDF or .TIF files using eFax Messenger. eFax documents can be converted from over fifty different email attachment file types in eFax software, including .PDF, .DOC, .JPG, .XLS, and .HTML.