power point has a compression utility in it, you can compress each picture invidually as you go.
You can break up your volumes with winrar to email size and send 1 volume in each email, once at destination to open the person will need all volumes to open. It does work I have done it many years ago.(
There is a program called fileminmizer that will also compress MS office ppt files, does really nice job, it is a pay for program, there is a free trial. I have compressed ppt files as much as 85 to 90 percent with hardly any loss in quality of the pictures.I bought it about a year ago , they had a special for 12.95..I see now its 44.00(expensive)
http://www.balesio.com/fileminimizer/eng/index.php theres the site if you have any interest.
Personally I would just break it into volumes with winrar and email it( winrar should still be able to do it, i havn't done it in years.)
Cattb