It
is always created or added by MUAs or delivery agents and never by MTAs. It should never
be declared in the configuration file.
25.12.11 Content-Transfer-Encoding:
Auxiliary MIME encoding RFC2045
The MIME Content-Transfer-Encoding: header describes what auxiliary encoding was
applied to the message body to allow it to pass through email transport mechanisms that
might have data or character set limitations. Specifically, RFC821 requires message bodies
to contain only 7-bit data. To transport 8-bit data (suchas images and sounds) unless 8-bit
is negotiated, it is necessary to convert that data to 7 bits. The Content-Transfer-Encoding:
header specifies precisely how that conversion was done:
Content-Transfer-Encoding: how
Here how is defined by RFC2045 to be one of the following: base64 (RFC2045), quotedprintable
(RFC2045, ?§24.9.45 on page 1025), 8bit (meaning that the message body
contains unencoded 8-bit data in line lengthsuitable for SMTP transport), 7bit (the
message body contains 7-bit, SMTP-compliant data), or binary (the message body contains
8-bit data in a form that is completely unsuitable for SMTP transport).
See the EightBitMode option (?§24.9.45 on page 1025) for a description of how V8 sendmail
converts between 8- and 7-bit data. The Content-Transfer-Encoding: header should never
be declared in the configuration file.
Pages:
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079