methods and apparatus in a wireless device for use in maintaining appropriate authentication credentials for receiving a message service provided by a service network which is external to a wireless network are described . the wireless device receives , via the wireless network , a data session configuration file which includes a list of a plurality of wireless networks mapped against authentication credentials associated with each said wireless network . the list includes authentication credentials associated with the wireless network . the wireless device submits , via the wireless network , the authentication credentials for establishing a data session via the wireless network . then , the wireless device receives , in the data session via the wireless network , the message service provided by the service network . prior to receiving the file , the wireless device may maintain default authentication credentials associated with a default wireless network , submit via the default wireless network the default authentication credentials for establishing a data session via the default wireless network , and receive in the data session via the default wireless network the message service provided by the service network .