Multiple users here are having the exact same problem and I can easily
reproduce it. If I send a message (I'm on Outlook) to a TB 8.0 user
with any attachment (we've tried both PDF and TIF) with a subject, but
no message body (including no signature), the problem occurs. In
their inbox, the message is shown without an attachment icon
(paperclip). If opened, there is no attachment shown. If you forward
the message, it shows the attachment filename and size, but if you try
to open it, it tries opening an nsmail*.tmp file (the * is a number
that varies) instead of the real filename. If you do forward that to
another person not using TB 8.0, then the attachment is there and can
be opened. If you look at the email's source in TB 8.0, the
attachment information is all there. This appears to be a bug in TB
8.0 as it worked fine for each of these users prior to the 8.0
update. For now, the workaround is to tell people to resend the email
with text in the body. However, even though this works, it doesn't
change the fact that this is a TB bug that needs to be fixed. As I
said, this is happening for multiple users here (everyone who has TB
8.0).
I've tried deleting the .msf indexing file for the Inbox so that it
recreates it in case that was somehow corrupted, but it didn't make
any difference.
Hopefully there will be an update to fix this bug soon. It's been
happening ever since the 8.0 release and is not convenient for
businesses who receive emails from a large number of users who may not
always include text in the message body.