-where you replace `1234567890@servicemail.foo` with the email address of the person you wish to reach (you can look up the email address for a given cellular provider online). Additionally, if you're not sure what cellular provider your friend has, there are online services where you can look up the number and determine the carrier.
+where you replace `1234567890@servicemail.foo` with the email address of the person you wish to reach (you can look up the email address for a given cellular provider online. See ). Additionally, if you're not sure what cellular provider your friend has, there are online services where you can look up the number and determine the carrier. For instance, try [http://www.whitepages.com/carrier_lookup](Free Cell Phone Carrier Lookup | Whitepages.com) (just enter in the "Mobile #" field, the "Name" and "Select Your Carrier" are unnecessary).