1. Find "Profile settings"
Press the Navigation key.
Select Messages.
Select Settings.
Select Text message.
Select SIM.
Select Profile settings.
2. Enter the message centre number
Highlight the required profile.
Press the Left selection key.
Select Edit.
Highlight the field below "SMSC address".
Key in +35387699989 and press the Left selection key.
+35387699989
Select Save.
3. Select validity period
Select Validity period.
Press Navigation key right to select Maximum.
4. Return to the home screen
Press Disconnect repeatedly to return to the home screen.