Ken,
By the looks of it, you never received a reply with a solution. Did you ever get the PDF attachement resolved?
I have a similar issue...and here's what I found (for those of you still looking for a solution)
Our Unix server generates pdf files of our invoices and emails them to our customers,
using a text2pdf converter v1.2 (from Pro-Sys Consultants)
If our customers atempt to open the email in smartermail, they get a message full of text characters
(i assume is the code of the pdf file) and NO ATTACHMENT!
Yet, if the same email message is downloaded to a client such as Outlook/ Outlook express, the attachment is readable!
After some digging around, I found that the PDF version (view properties on a pdf file and click the "PDF" tab)
on the "unreadable" attachments is 1.1, yet when I send a pdf in version 1.4 or 1.5, it is "readable".
Seems to be an issue with the PDF Version. I'll post back later.
Puas
PS. There is another option within the "PDF" tab, "Fast Web View"...seemed to be a likely culprit, but after some testing, made no difference.