The .att file extension is most commonly associated with Web Form Post data files. These files are created when a visitor to a website uses a Web form to submit information in a Web browser. The ATT files contain the contents of the Web form. The ATT file is emailed to the recipient that has been designated by the Web programmer and is attached to the email with the .att file extension.
The .att file extension is also used for AT&T Group 4 bitmap graphic files, Alphacam lathe tool files, SeeYou waypoint files and ZipLip secure e-mail files.
Try a universal file viewer
File.org aims to be the go-to resource for file type- and related software information. We spend countless hours researching various file formats and software that can open, convert, create or otherwise work with those files.
If you have additional information about the ATT file format or software that uses files with the ATT suffix, please do get in touch - we would love hearing from you.