F=7
Strip the high bit when delivering V8.6 and later
Under old versions of sendmail,
all lines of text output by
sendmail (including the
header and body of a message) automatically have the
high bit cleared (zeroed) for every character. This
behavior remains unchanged under V8
sendmail for configuration
file versions 2 or less (The V Configuration Command on page
580). But with version 3 and later configuration
files, the message body is transmitted with the high
bit intact by default. For those delivery agents
that should not allow 8-bit data to be transmitted,
you can use the F=7 delivery agent flag to force the
old behavior.
Beginning with V8.7, the F=7 delivery agent flag can be used to
suppress certain kinds of MIME conversions. For
example, if the EightBitMode option (EightBitMode on page 1025) is set to
p (pass 8) and
if the message contains 8-bit MIME data in its body,
this F=7 delivery
agent flag will force sendmail
to bounce the message with the following SMTP error,
and to exit with EX_DATAERR:
554 5.6.3 Cannot send 8-bit data to 7-bit destination
Note that F=7
affects only the message body. Headers always have
the high bit cleared.
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