How to Add a Client Certificate in TouchDown for iOS
To add a client certificate in iOS, you will need to have the .pfx file on your desktop.
Plug in your device to your computer
Open iTunes and click on your device
Click the Apps tab
Select Touchdown for iOS on the left hand side Apps menu
Tap the Add button under the Touchdown documents menu
Find and select the .pfx provided by your IT team
Return to your device and configure Touchdown using your newly added client certificate.