[log in to unmask] said:

> Problem Summary
> ---------------
> If the "Content-Type:" mail header in
> an incoming mail message is longer than 80 characters, the listserver
> (or the SMTP server used by the listserver) wraps and indents the
> header onto multiple lines before distributing the message.  If the
> wrap (newline) and indent (space) characters are inserted within the
> "Boundary=" parameter of the header, some mail user agents are unable
> to locate and differentiate attachments in the body of the mail
> message.

I think RFC822 says:

1) Quoted strings (qtext) may be folded.  See Appendix D
2) There is no syntactic difference between a single linear-white-space
   character and multiple contiguous linear-white-space characters in
   structured field bodies.  See Section 3.4.2

If so, the MUAs having trouble with folded boundary strings are broken.

Glenn