Setting Up Data Services on 8230
I have an 8220, not an 8230, and don't use the Internet on it, but I do know that you have to set up data services to use the Internet and send picture messages--and I have done latter successfully on my unlocked 8220. So, these are the two steps I suggest.
1. Find the APN (access point name) for TCP for your carrier. (You should be able to get this information from your carrier's Web site.) On your phone, go to the Options icon, open it and select Advanced Options. Then select TCP/IP. Make sure that APN settings are enabled and fill in the required APN on the second line (you probably will have to replace a previous entry). See the T-Mobile instructions for this operation as an example: T-Mobile Support Community: Set the TCP and Access Point Name (APN) settings on the device - BlackBerry (All Devices).
2. If you haven't already, download from RIM the Blackberry User Guide for your phone: BlackBerry Pearl - Manuals and Guides. It has more instructions on how to set up and use data services on the phone. (In addition to enabling APN settings and entering the correct APN, you will need at least to be sure your browser is correctly configured.)