This is attached by Outlook or Word. Sender may not know, that he attach anything during composing the email. Perhaps it's the background of the e-mail.

Any idea what the blank image is?

I google that file name and see it reported over a period as PDF files being renamed by outlook. but I see nothing definative.

My guess, given the the ~ character is one used by window to creating dos style 8.3 file names that somewhere in the mix we have an anti virus program scrambling intended attachments. My guess is the mails come to you with an image somewhere like in the signature.

What difference can you see if you access the mail from your providers web site.

Matt said

Any idea what the blank image is? I google that file name and see it reported over a period as PDF files being renamed by outlook. but I see nothing definative. My guess, given the the ~ character is one used by window to creating dos style 8.3 file names that somewhere in the mix we have an anti virus program scrambling intended attachments. My guess is the mails come to you with an image somewhere like in the signature. What difference can you see if you access the mail from your providers web site.

No idea what the blank image is; and there are no such attachments from my email provider!