Attachments in every email received

["Nathan Simpson" <nathansimpson@xxxxxxxxxxxxxxx>]

Hi,

We are still running 4.6 and are upgrading soon but need to get this fixed
in the mean time.

In all of the emails received in Notes from the outside world there is an
attachment named 'att1.eml'. If I send from an internal Notes client to
another it doesn't appear.

If you open it up it is the actual contents of the email plus all of the
mail servers it passed through etc.

How can I stop receiving emails in this format? i.e. without the attachment.
The end users don't need to know this type of information.

TIA

Nathan Simpson