I had this problem all last night as well as with mms messaging. I did a bit of reserching and this fixed both sms and mms messaging for my a008. Hopefully, it'll do the same for you... =]
Ok, these are the setting that I have with T-Mobile. It should work, as it does with my A008
Note: This is for using with the T-MobileWeb (the slow and cheap one) service with T-Mobile. If you are using the Full Internet service, forget about it. The A008 does not have enough memory to do real HTML internet.
-and then "Data Account" on the phone.
-If you don't see the T-Mobile GPRS configuration in the list, create one your self
-To create one, select ANY existing configuration and edit it.
-For example, since the phone is likely from Hong Kong, you probably will see a config called "FET GPRS". Select that and edit
-After selecting a configuration and pressed "edit", you should be able to modify the account name, the APN, username, password, and the Auth. type
-Change the account name to "T-Mobile"
-Change the APN to wap.voicestream.com
-leave username and password empty
-change Auth.type to normal
-when asked, click "save"
Now we are done with the "Data Account" portion of the setting.
Next we have to modify the "WAP" portion.
-Select "WAP, under "Services"
-select "Edit Profile"
-select whatever sim that your are using. Sim 1 or Sim 2
-Like before with the Data Account, either find or create your own profile by selecting ANY existing profile
-select "Edit Profile"
-Change the name to whatever you want. "T-Mobile" if you are not creative
-Change the Homepage to http://wap.myvoicestream.com
-Change the data account to GPRS --> "T-Mobile"
-Change the Connection Type to "WAP"
-The IP address is 216.155.165.050
-Leave the username and the password blank
-press "back" and "Activate Profile"
Wow, that was longer than what I wanted....
Hope this will work for you
For MMS settings
*MUST config the above internet settings before for this to work*
-Select "MMS setting"
-Select "Server profile"
-Choose whatever SIM card you are using
-Select ANY existing profile and "Edit Profile"
-Rename the profile to "T-Mobile MMS"
-Change the Homepage to http://126.96.36.199/servlets/mms
-Change the data account to GPRS ---> "T-Mobile"
-Change connection type to "WAP"
-Leave username and password blank