Thank you all for your help. I have tried the above steps and now it's just a waiting game to see if it happens again, because you can't tell right away. Most of the time the users were getting their emails there was just those few times that it didn't push through to their desktop version and they found out by the customer being upset that my user didn't respond. So, if you don't hear back from me then it worked!! Thank you again!
Shauna