Unwanted small .gifs inserted in outgoing emails

[Rick Allen]

When I send an email, 8 small green squares (.gifs) are attached to the outgoing email. They don't appear in the sent email in my sent folder, I only know it is happening because people come back to me asking why they are there

I have removed and re-installed Outlook 2002 and they stopped for a day or 2 and now they are back in my sent emails again. Where are they coming from and what do I do to stop it

Thanks and regards