$={checkMIMEHeaders}
MIME headers for maximum legal length checking V8.10 and later
Beginning with V8.10 sendmail,
the MaxMimeHeaderLength option (MaxMimeHeaderLength on page 1047) can
be used to define the maximum length for selected
MIME headers. Before making that check,
sendmail looks to see whether
a particular header is in the class $={checkMIMEHeaders}. If
it isn’t, sendmail skips this
length check.
When V8.10 sendmail starts up, it
predefines the $={checkMIMEHeaders} class to contain
five MIME headers: the Content-Disposition: header (Content-Disposition: on page
1153); the Content-Id: header (Content-Id: on page 1153); the
Content-Transfer-Encoding: header
(Content-Transfer-Encoding:
on page 1154); the Content-Type: header (Content-Type: on page 1154); and
the MIME-Version:
header (MIME-Version: on page
1160). You can add more headers with the C or F configuration file
command.
If any of these headers are found to be too long, they
are truncated to the length specified by the
MaxMimeHeaderLength option (MaxMimeHeaderLength on page 1047).
Note that this truncation is done carefully so as to
maintain the appearance of an RFC2822-legal
header.
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