Using E-Mail to send large files always accounts for trouble, since E-Mail wasn't really designed to transport huge amount of data or share large files. There are other products out there (like x-drive (http://www.xdrive.com) which do the job better.
However, people still want the convenient way of sending a piece of mail and at the same time share something they think is worth sharing - no matter what the size.
So AOL Webmail decided to integrate with xdrive. Now you can send attachments up to 5 Gigabyte convenient using AOL Webmail, while the actual attachment gets shared via X-Drive. This is totally transparent and simple.
The service is currently in beta and you can try it by going to http://beta.webmail.aol.com. When you compose a message and click on "Attachments" be sure to mark the checkbox which says "Upload to X-Drive" The rest is simple and just like attaching any other file.