Opencart not notifying customers via email

Hello,

I have ShipRush integrated w/ Opencart.. everything works great.. it pulls orders correctly, updates the orders with the shipping info, and sets the field that it notified the customer to yes, but it never actually notifies the customer. I've watched the mail logs on the server and nada. Not seeing any errors either.

Here's the webserver log - this is the post once I printed the shipping label w/ the Desktop software:

72.32.30.88 - - [08/Aug/2014:20:52:36 -0500] "GET /ShippingZOpencart.php?Shipping_Access_Token=<remov ed>&cmd=updateshippinginfo&OrderNumber=79&Tracking Number=866804810000100&Carrier=FedEx&Service=FedEx +Home+Delivery%C2%AE&ShippingCost=9.74 HTTP/1.0" 200 94 "-" "-"

and the order has the following in its History:

09/08/2014 Shipped on 08/09/2014 via FedEx [FedEx Home Delivery ?], Tracking number 866804810000100 Shipped Yes

I'm running Opencart 1.5.6.2

Thanks for your help