$=e
Encode this Content-Transfer-Encoding: V8.7 and later
The F=7
delivery
agent flag (F=7 on page
764) determines whether MIME-encoded data should be
converted from 8 to 7 bits. If the message is in
8-bit format and if it is going to a MIME-capable
destination that requires 7-bit data, the message
body will be converted to 7 bits by using either
quoted-printable or Base64 (EightBitMode on page 1025).
Not all datatypes should be converted to 7 bits,
however. The types that might possibly be converted
are listed with the Content-Transfer-Encoding
: header
(Content-Transfer-Encoding:
on page 1154). One type that should not be
converted, for example, is the quoted-printable
type
because it is already converted. Types that can be
converted are 7bit
, 8bit
, and binary
.
Beginning with V8.7 sendmail, the
class $=e
is used
to determine whether a type will be encoded. Only
those values listed in this class will be encoded.
When sendmail first starts, it
initializes the list of values in class $=e
to be:
7bit 8bit binary
You can add types to this class, but you can never remove them.
Note that a type in class $=e
can still be prevented from being
encoded on the basis of the considerations imposed
by class $=n
.
Also note that the actual encoding can be restricted
to quoted-printable by use of the class $=q
.
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