How do I compact/compress photo email attachment using Outlook Express?

don't think u can it might not b good enuf.

you can't with outlook either post the image to a photo site like photobucket.com and put the link in the email. Or use a photo editing program (like paint.net) or website (like picnik.com) to resize it.

You don't, you use another program to compress the image, such as 7-zip or WinRAR, or better of open the picture in an image editing program, and save it as a JPEG image, which is an already compressed picture format.