Outlook blocking external images

[vbcode1980]

Hi,

Our company is preparing to send out an email mailing.
This mailing uses external images that are saved on our webserver.

We've done some tests to see if the email is shown correctly in a number of email clients.

Outlook 2003 blocks the external images by default.
This is not a problem, because usually it shows a link saying "Click here to download images" which will download the external images.
However, with our mailing, it doesn't.
The images are simply removed, there are no red 'X's, or links to download the images.

This behavior goes away if I add the recipient to my safe list, or change some settings in Outlook.
Most of our clients won't have us on their safe list.
And since there's no sign that any images are being blocked, they won't change their settings either...

Does anyone know how to counter this behavior, without requiring the receivers to do anything?

Cheers,
VBCode1980