USPS URL not being emailed to customer correctly, need some help?

[tsbyty]

Hello,

I only ship with USPS, so for tracking information for my customers I have added the URL: http://trkcnfrm1.smi.usps.com/PTSInternetWeb/InterLabelInquiry.do?origTrackNum=@

to the back office/carriers/ and added this url. When the email is sent to my customer with the tracking number, it changes the url to something else, here is the example:
http://trkcnfrm1.smi.usps.com/PTSInternetWeb/index.jsp0180 5213 9075 3363 5744 I'm not sure how it's changing it to index.jsp How do I correct this?

The tracking number should be where the @ symbol is above for the first URL. What do I need to change to ensure that the link is emailed correctly? I'm using Version 1.3.1.1