Storage of incoming messages
When you have an incoming text message and your phone’s 
memory is full, one or more low-priority messages, which 
have been read, will automatically be deleted in order to 
receive the new text message. Messages are usually deleted 
from your Inbox, but an emergency message may cause 
messages to be deleted from the Saved folder.
If the message memory is still full, your phone will display 
No space: message waiting. You can clear this notification 
by pressing OK. You should delete one or more old messages 
to make room for the new message. The network will 
re-send the message at a later time.