Encode or decode message bodies for 8bit transfer encoding. This is
only very little encoding. According to the specs:
RFC-2045 Section 2.8 defines legal 8bit data:
"8bit data" refers to data that is all represented as relatively
short lines with 998 octets or less between CRLF line separation
sequences [RFC-821]), but octets with decimal values greater than 127
may be used. As with "7bit data" CR and LF octets only occur as part
of CRLF line separation sequences and no NULs are allowed.
As you can safely conclude: decoding of these bodies is no work
See documentation in the base class.