Only the data fork of documents will be sent, with “UUencode”; best for communicating with archaic systems.

Documents will be sent with “BinHex”; most compatible with old Mac mailers.

Documents will be sent with “AppleSingle”; acceptable for sending applications or other Mac-specific files.

Documents will be sent with “AppleDouble”; best for recipients with MIME.

Use this menu to determine how attachments will be sent.