The following have participated with the National Postal Museum on its “America’s Mailing Industry” project and can be sources of additional information about particular aspects of the mailing industry.
- United States Postal Service
- Association for Suppliers of Printing, Publishing and Converting Technologies
- Alliance of Nonprofit Mailers
- American Catalog Mailers Association
- American Forest & Paper Association
- Association of Magazine Media
- Association for Postal Commerce
- Direct Marketing Association
- Envelope Manufacturers Association
- Idealliance
- International Mailers Advisory Group
- National Newspaper Association
- National Postal Policy Council
- National Star Route Mail Contractors Association
- Parcel Shippers Association
