AC 24.2025

May 5, 2025

Memorandum to Federal Records Management Contacts: Update to File Formats Guidance for Email Records

I am pleased to announce that NARA has updated Appendix A: Table of File Formats of NARA Bulletin 2014-04, Format Guidance for the Transfer of Permanent Electronic Records. 

We have recategorized the format Microsoft Personal Folder Format (PST) with ANSI textual encoding as a format that is appropriate for imminent transfer. It was previously categorized as an acceptable format. PST (ANSI) was the default format for Microsoft Outlook 1997-2002 and is now considered a legacy format. 

Agencies maintaining permanent email records in PST (ANSI) format should contact their processing archivist and arrange to transfer these records to NARA as soon as practicable.
If you have any questions regarding these updates to file formats for permanent electronic records, please contact rmstandards@nara.gov.

William Fischer   
Chief Records Officer 
for the U.S. Government (Acting)