Why can i not send text messages with my nokia 2760

SOURCE: Nokia 5300 Wont Send Text Messages

i had the same problem. first try turning the phone off then back on and if it doesnt work after that then go into menu>optus>SIM Backup and turn it on
worked for me

SOURCE: Unable to text

Hi,
This is a common problem. But there is a solution for this problem.
go to Messaging. Then hit Options. Scroll down to settings.
Hit text message. Options - Then "Message Centres".
Hit the Edit button and the following number should come up:

+47973100973
Save it and try sending messages. If again the same problem exist then call up your customer care who provides the services of your phone like Airtel, Reliance etc.. Ask the message center number and follow the above steps and save that service center number. Hopefully it should work. Thank you......

SOURCE: My Nokia N73 cant recieve text messages, it can send but cant receive.... :(

you need to format your phone so that you can receive messages again...input this code *#7370# and then click yes...enter your security code...after that your phone will reboot...it will automatically on..so please wait until the phone open..after that enjoy texting again..hope this will help you

SOURCE: can't send text message. "unable to send message"

Hi,
check your message centre number..If its edited or deleted..u cant send or receive any messages..contact your operator for tat number..

SOURCE: N5530 -Cannot send and receive text messages

Switch-off your phone. 1. Press and hold 3
keys; Green dial key, *
Star key, no. 3 key on keypad and then press
the power on/off to
swtich on the phone. Remember, do not let go the 3
press and hold
keys until you see a formatting word screen show! 2.
After a few
minutes when the Full phone formatting completed, your phone
will
back to original system and factory settting.