If ActiveSync cannot receive data through Port 990
A computer uses logical connections called "ports" to pass data into and out of the computer. ActiveSync uses port 990 to send its data into the computer. If the Troubleshooter for ActiveSync detects data being blocked, follow these steps:
Check the Windows Mobile powered device display for any messages and respond to them before continuing.
Ensure that the computer and the device are set up to use USB connections for ActiveSync:
In ActiveSync on the computer: On the File menu, click Connection Settings and select the Allow USB connections check box.
In ActiveSync on your device: Click Menu > Connections and select the Synchronize all PCs using this connection check box.
Ensure that the device is connected to the computer using the USB cable that came with the device.
