Even tho yahoo allows 25 MB, that doesn't mean it's RELIABLE.  The issue is with the number of packets zipping through cyberspace.  The more packets, the more likely there is to be a problem. 

Also, while Robert's advice regarding scanner settings is sound, Helene may find that setting HER scanner at 600 dpi will INCREASE the size, rather than decrease.  We've found huge differences between our two printers and they're both Brother.  The max I can scan at (setting it for B&W, of course) is 300 dpi in order to keep a file a reasonable size.  I can even go to 144 dpi with clear images.

The ultimate solution to your problem is to use an on-line service for large file transfer.  There are many out there that are reliable and totally free.  You can just e-mail a link to your client and they can retrieve their file that way.  I believe if you click on the link, it doesn't even take you to the file site...it just downloads it for you.  You'll have to play a little bit.  Do a search for "free large file transfers" or something along that line.

If you have a server yourself, you can send an ftp link to your owner server.  That's what we do.