Junk Email in Outlook 2003

[melito]

I'm not quite sure if this is the correct forum for this. Anyway, some of the
users in our organization are receiving emails in the junk email folder but
some are not. The email sent to users are all the same and sent at the same
time from an application.
The junk email is happening on the Outlook client. All Outlook configuration
for our organization are all the same since we are using an image and I can
confirm that users did not modify anything.

Any idea will be appreciated.

Thanks in advance.