I have the same problem. I took a picture in portrait mode and transferred it to my pc. It would not rotate and ended up shown on sideways. So are the video's. Good thing is that these are test shot since I got my i6 recently. From now on, I will take pictures in landscape mode to avoid this problem.
Sorry, I was mistaken. I checked my iphone4 test shots again. Photos are ok, they do display properly on my computer (I transfer them directly from my iphone4 to my computer, not via email, and I am not JB).
Video is another story. It has to be taken in landscape mode. It will not rotate.
Maybe you should try transferring your photos to your computer directly and see what happens. Just connect iphone4 to any pc, it will show a DCIM file and you can copy and paste into your pc.
But, still does not solve your email problem.
You mean I should use the white cable, you sync your iphone to your computer with in order to get the pictures in the right position? Yes, I would think that would work. But the fun in having an iPhone is to be out there (wherever) and email the picture or video you just took to a friend or relative. It is so easy to do but then everybody wrote back to me that it arrived sideways and jokingly said, they would have to lay on the floor in order to see it. So there is no fun in sending pictures like that and not everybody has an iphone. It is annoying and takes away the fun in sending pictures on the go.