Just a couple of questions: Is it that they say the image is too big, so they only can print some of it? Does sending it as a Netscape image mean that the image opens in the recipients browser because it is set within an HTML document? If so, a problem arises because of the d.p.i browsers display images at (72 d.p.i). If the dpi of the image sent is maybe 96 d.p.i or more, the image will look and print too big. Now, I have to admit that I've never put this to the test because I don't want to waste lots of ink doing so

but have read articles on the subject and this could be a reason for the problem.
The best thing to do is to suggest to those receiving the image files that they save the image to disk (not within the HTML document), resize it in an image editing program and then print it from there.