keisha,
Your inquiry is a bit vague. What image format are you saving to?
When you say, "the picture doesn’t load," does that mean your email recipient can’t open it? If that’s the case, I doubt it has anything to do with Photoshop per se.
Can you be more specific?
Without a discussion on image degradation, resolution, up or resampling –the following is an example that I would like you to try step by step:
For email ettiquet: try setting a duplicate image doc. using IMage > Image size. In the dialog, hange the rez on the lowest box to 72ppi. Then check the "Resample" checkmark and in the upper part of the box type in 640 pixels for you longest edge and then hit OK.
Now go to File > Save for Web. Choose your "Medium" 30 to 50, whatever is around 34 to >100 kb. and OK. Then save this as "newlowrez.JPG" image to a Websend folder.
Meanwhile, back in Photoshop, you still have a now, low rez dupe of your full-sized image in .psd format. You have 3 options.
Close without saving to get rid of it permanently,
or save it where you put low rez images not for print,
or return it to high rez by clicking the start of all History states.
Now, if you are not sure it is the correct size for viewing etc., go to your email and send your Websend/"newlowrezjpg.doc" you saved –to yourself.
In a few seconds, you can see how others will see it.