I'm inclined now to agree with Tim that there is indeed something wrong
in regards to multipart messages.  I'm working on a specialized MUA
which among other things stresses being able to drill down through
complex multipart MIME messages.  I'm finding that if the message itself
is multipart, everything is OK, it's sub-parts being multipart where you
run into trouble.  At some point when a "part" of the message is
accessed, the parts field of that MailMessage is set to an empty Array,
the problem is that MailMessage>>parts will only attempt to parse for
parts if parts is set to nil, which of course it no longer is.  I'm
still hunting for the culprit, but I thought I would send out this
notice in case someone more experienced with MailMessage would get a
lightbulb on reading this.

Ken Causey