This is an old revision of the document!
https://www.developershome.com/sms/cmgrCommand2.asp
First, enter the command line “AT+CMGF=1” in a terminal program (for example, HyperTerminal in Microsoft Windows) to instruct the GSM/GPRS modem or mobile phone to operate in SMS text mode. This step is necessary because the default mode is SMS PDU mode.
AT+CMGF=1 OK
Second, use the AT command +CPMS (command name in text: Preferred Message Storage) to select the message storage area to read SMS text messages from. For example, to instruct the GSM/GPRS modem or mobile phone to use the message storage area in the SIM card for the AT command +CMGR, enter the command line 'AT+CPMS=“SM”' in the terminal program (more details here)
AT+CPMS="SM","SM" +CPMS: 2,10,2,10,3,160 OK
Third, you can now use the +CMGR AT command to read a text message from the message storage area. Let's say you would like to read the text message at index 1
AT+CMGR=1
To send SMS
AT+CMGS="xxxxxx"
To store SMS without sending
AT+CMGW="xxxxx"
To send similar message to multiple recipient
** use the AT+CMGW to store the message and get message location number ** AT+CMSS=id,"xxxxxx"