Step 1 – Download Irfanview from
http://www.tucows.com/get/194967_75076 (can be downloaded from other
sites, just Google "Irfanview"
Step 2 – Install Irfanview (find the file you just downloaded and
double click on it, should be titled similar to iview399.exe)
Step 3 – Open Irfanview
Step 4 – Open the photo you wish to reduce
Step 5 – Resize the image by clicking Image>Resize/Resample (or by
Cntrl-R). I usually set the image to 800x600 or 640x480 if I'm
emailing it. The "Set new size as percentage of original" option
works well too.
Step 6 – Save the file (as jpeg preferably). Check the "Show options
dialog" button. This allows you to specify the quality. Play with
the quality to find the right compromise between file size and
quality. 50-75% works well in most cases for me.
Step 7 – Check the file size before sending. Just right click on the
file a click properties. You should be able to get each picture to be
less than 100k without degrading the quality very much.