Vista - Emailing Photos - Problem

Hi,
I am using Office Basic Edition 2003 with Outlook as my email program. In
the past I have been able to insert many photos in an email without the email
becoming a large file. I have started with around 1MB jpeg files and they
have been reduced in size and included as pictures in the email. (Insert,
picture, from file) The email has remained small.
Recently using the same process I have ended up with huge emails, as an
example four 1MB photos ended up creating an email file of 21MB!!!
Can anyone help with what I can do to get each pictue down to say less than
100KB so I can email maybe 20 pictures at a time.
I can insert the full sized files in an email satisfactorily, but 20
pictures of 1MB will give me a 20MB+ email file size which is unrealistic to
handle, hence at the moment I have been reduced to sending pictures 2 or 3 at
a time. Not efficient time wise.