/ENCODING=encoding

    Specify the encoding method to use to encode an input message
    file. Normally, no encoding is used; however, this depends upon
    the file type as determined by the file extension. The available
    encoding methods are BASE32, BASE64, CBASE64 (compressed base64),
    BASE85, BINHEX, BTOA HEXADECIMAL, PATHWORKS, QUOTED_PRINTABLE,
    UUENCODE, and CUUENCODE (compressed UUENCODE). No encoding can be
    specified for a file containing header information (/HEADERS).