[Mimedefang] Truncated long MIME Content-Transfer-Encoding header

[Jon Fullmer]

Some jerk has been sending me spam that has consistently triggered these
messages within sendmail:

Truncated long MIME Content-Transfer-Encoding header (length = 435)
(possible attack)

I haven't seen messages like this, well, probably ever.  Because of this, I
suspect I can safely configure MIMEDefang to reject a message with a
truncated long MIME header.  I studied the mimedefang-filter (and the
example) and Googled, but I can't seem to see any way to do this.  Is there
a way?

 - Jon