Alex try to reduce the image sizes in Photoshop.
I will right down here the steps to try and help you.
-Open picture in Photoshop
-go to image > image size > a dialog box will open > right in "Width" box 800 pixels.
- If you have constrain proportions on it will make a 800 X 600 image of your file.
Then save your picture as as Jpeg - quality 7.
By doing these steps you should have some good sized pictures to send via e-mail.
Hope this helps!