Hi Jamar,
If you’re finding it works as expected in your own tests that tends to suggest the functionality is working – but of course that doesn’t mean the customers are not encountering problems.
Might it be the emails are being directed into the spam folders in the case of those affected customers? Are all your customers reporting this problem?
I’m also curious about the sort of email setup are you using – is it the built-in email that comes as part of the package (are you using a regular shared hosting account), or have you hooked up a dedicated email service or anything of that nature?
Thanks!