Each time you connect to your Internet on your BlackBerry Bold, you are using the access point network (APN) settings from your mobile network. If the APN settings aren't correct, you can't receive multimedia message services, connect to the web browser or use some of the third-party applications on your BlackBerry Bold. Each mobile service company has their own APN settings and you must enter the correct settings for your mobile network.
Turn on your BlackBerry Bold by pressing the end call/power button until the screen lights up. Press the menu key to open up the applications list.
Click "Settings" and then click "Options." Click "Advanced Options." Click "TCP."
Enter the APN settings for your mobile provider into their fields. Press the menu key and then click "Save."
In most cases, if your BlackBerry Bold is branded to your current carrier the APN settings are already correct. However, if you are using an unlocked BlackBerry Bold on another network, configuring the APN settings is required.
Each mobile service provider has its own APN settings that they can change them as they wish. If you are having trouble with your phone's APN settings, you should contact your mobile provider's customer service centre. They will have the most current settings on file.