emailing from iphoto sends as bitmaps not jpegs

[BeHappy]

Hello,

I'm new user to mac and I have problem, all of my iphotos that I email to friends with Windows show up to them as bitmap format, not jpeg.
And to mention, my pictures show as jpeg when I send them, but recipient can save them only as bitmap.

Is there some trick to correct it?

Thanx a lot!