Vista - blank emails

I am having a problem with windows mail vista. People who send me emails
keep getting a blank email from me as soon as they send me the email like
its automatically sent to them from me but its blank. I still get the email
and can read it but I am not replying or sending anything out. Any info on
this problem would be appreciated...thanks in advance. P. S. I called my
server with whom I have my internet through and they said it was a glitch or
something with windows mail and we tried a few things to correct it but with
no luck.