Emailed Links not working

What a great product this is!! It does everything I need.

I’m only having one problem. The links in the email back to the customer don’t work. The link is there and it looks like it should work but it doesn’t.

I have tried both text email and html email.

I saw something earlier in the thread about hyphens in the file name screwing up the email and all of my filenames have underscores, but I took them out for a test and it didn’t do any good. My data is in wp-content, so I can’t get rid of all the hyphens.

the web address is http://quickbookshelpebooks.com

If you order one of the free books you can see what I mean.

Thank you for this!!

http://wordpress.org/extend/plugins/easy-digital-downloads/