how to convert large pic files for e-mail

Well what I use is the free program called Photofiltre. You can easily re-size pictures in there, and even do it in batches:

http://photofiltre.free.fr/download_en.htm

I use the nikon transfer software to transfer the pictures to my computer from my nikon camera. Now all the picture files are over 2 mb in size, way to big for e-mail.

I do not know what program to use to make the pictures more reasonable for e-mail.