After getting a heads-up from a form user, I tested the form myself and have not received the email receipt confirmation. I double checked settings; everything looks good. Is there a current known issue with submission receipts?
I'm looking into this. Can you send me a private message with what domain your email account is on? If it's a work domain, can you tell me if your work has a spam filter or uses a product like Postini?
Turns out the problem was on my mail server. Got it fixed up with Todd's help. Thanks, Todd!