Name
$=s
Synopsis
An email message as
defined by RFC822 cannot contain 8-bit data. Consequently, when the
MIME Content-Type: header declares a message
subtype that is rfc822, we immediately know that
it will contain nothing that needs 8- to 7-bit encoding:
Content-Type: message/rfc822
As other message subtypes evolve, this assumption can safely be made
about them too. So to make sendmail more
adaptable, the $=s class was added beginning with
V8.7. This class contains a list of subtypes that should be treated
the same as rfc822. When
sendmail first begins to run, it initializes
that list to contain:
rfc822
Other subtypes that can legitimately appear here might be
partial or delivery-status.
Note that this provides only an initial hint to
sendmail. The rfc822 subtype
can itself contain MIME information that might require 8- to 7-bit
encoding.
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