You can use many different programs to resize and compress images such as Microsoft Office Picture Manager, Adobe Photoshop Elements, Microsoft Picture It! and others.
Before emailing pictures to freinds and family, try to resize your images to under 100K per attachment or no bigger than 600 pixels wide or 500 pixels tall.
This is in order to make the download easier and faster for the person receiving the email.
To resize an image:
Select the image you wish to edit.
Select the Single Picture View.
Click on Resize in the Edit Pictures task pane or select Picture.
Resize to display the Resize task pane.
Adjust the size of the image. Click on OK.