hrown if the Content-Type
 of the MimeMultipart does not include a <code>boundary</code> parameter.
 If this property is set to <code>true</code> or not set, the multipart
 parsing code will look for a line that looks like a bounary line and
 use that as the boundary separating the parts. <p>

 The <code>mail.mime.multipart.ignoreexistingboundaryparameter</code>
 System property may be set to <code>true</code> to cause any boundary
 to be ignored and instead search for a boundary line in the message
 as wit