Yeah, it looks like we're not going to resolve this. If anyone else has some thoughts on this, please speak up.
Just changed break apart message length to longer than 120kb - was at default 60kb
Have you tried disabling that option altogether? I've never used it; never saw a need to use it.
Do you also have Outlook, part of MS Office, on your computer?
I can send and receive other attachments Ok in express -
Are any of these files as large as your PDF files?