"Ian McCulloch" wrote in
:

Outlook 2003 - unable to have the attachment option appear where the
attachment appears as a line item below the subject field

Stop using RTF (Rich-Text Format) which shows the attachments inline
with the body of your message.

Only Outlook understands RTF. No other e-mail clients understand RTF
which means they will show a winmail.dat attachment when they receive
your RTF message. Outlook understands RTF so it hides that there is a
winmail.dat file containing that proprietary formatting of the message.
RTF should only be used when it is guaranteed that the recipient is also
using Outlook and within the same Exchange mail server organization.