I have tried to look for some feedback on a problem I have with my Mail.app (Tiger), being this:

In several occasions when I send a long e-mail message which includes attached files, I have received claims from the recipients, that they receive my message with a blank content (not event my signature), wherein all of the attached PDF's, images or whatever was sent do appears attached to the message, and also the content of my message being this the written text, is converted into a "txt" file and putted in the attached files section.

This is really annoying me in terms that I use mail.app for my corporate e-mail, and I am starting to receive claims from my clients. Consider that if the person who receives the file doesn't looks at the attached "txt" file, and notes that there do was a message content written, and it wasn't that you just attached a couple of files and wrote nothing, they will consider your action as rude.

Initially I thought the problem was based on the content being in Rich Format, so I changed it to Plain Text, and now I have confirmed that the problem happens with both text configurations.

I have searched in Google and Apple's Support pages without finding any answer. Please provide me with some information or the cure for this problem if someone knows about it.

Thanks in advance for any help.