I know this isn't a good answer but I've heard all kinds of issues with GoDaddy servers. I have no problem with their core registration business, but I've never had any luck with resolving other issues with their support. I spent a week trying to get them to understand that I couldn't go to my data center in another part of the country and send a test message directly from the "screen" to their email servers. They seemed completely unaware that web sites were able to send email automatically. Their servers were just discarding email without any notice to sender or receiver. My client finally just switched services.
See if this article helps:
GoDaddy Form Mail Woes