Every email has attachment

[Jeff]

Please help me solve this problem.
Every email I receive has a text file attached with the
email subject as its file name. The content of the text
file is the same content in the email.
This all of a sudden started happening today, any ideas?

For example: You send me an email
Subject: hello
Text: Hi how are you?

And I will receive that exact email EXCEPT it will also
have a hello.txt file. In this file will be the text "Hi
how are you?"

Thanks,
Jeff