SMS sending failed

If you do not have at least 2 steady bars of reception strength, text messages or pic messages could fail sometimes. If these fail no matter what signal strength, you should contact your phone provider (StraightTalk).

there are several factors why you are unable to send and receive messages and make outgoing calls and receive incoming calls.
network issue: are you the only one experiencing the problem? try to check with someone who is on the same location and is using the same network as you if he or she is experiencing the same problem as you. if yes, then it may be a problem with your network.
make sure that you have good signal and contact your service provider too and ask them if they have an ongoing maintenance in the area and ask if the sms and calls services are activated on your account
phone issue: if you have a good signal and still can't send, receive text messages, do and receive incoming, outgoing calls, try to do these: call the service provider and ask for the default network pin, then go to the settings of your phone, call settings, call barring, deactivate all barring
try inserting your sim card to another phone and try to send an sms
turn off your phone, remove battery and sim card and then wait for a few seconds, then put back the sim and battery and turn on the phone then try to send an sms

That means your sms storage is full. Delete the SMS/MMS and you should be able to send/receive new messages.

This could only be caused by a couple of things. The message center number in the handset may not be correct, which will cause the messages to fail. The other possibility is that the feature is not active on your account with your wireless provider. What you need to do is test a couple of things. See if you can send a text/sms message to yourself, in doing this you can verify that you can not only send, but receive text/sms messages. If you cannot send, or receive text/sms messages, then that verifies that the message/service center number is off, and will need to be corrected. If that works, and you can receive text/sms messages, then your service center number is correct, and you will move to the next troubleshooting step, which is to test your web browser. If you cannot launch the web browser on your handset, then this is an issue, because the MMS service requires that you have both SMS, and web browser service to send a MMS message. If you can access the internet and you have the ability to send/receive text/sms, then you need to call your service provider as the issue may be with their service.

bad signal area ( try and get at least 2 bars signal strength, ensure enough credit on your account if that fails, consider getting a new phone. Good Luck

you have wrong network seleckted you can change settings in icon messages there settings and there you can find network options then choose your network.

Full working!!!!
I solved SMS sending problem with E61

Just hard resset your NOKIA phone by pressing in same time this four buttons:
1) * (star) button
2) 3 button
3) green tab (call acceptance ) button
4) power on - button

NOTE Press all this in same time and wait until phone load.

this should be happening because of SMS memory full ... after it the messeges can not be sent .. or can be the connection problem..

try to update or re-install software of ur phone.
but first back up ur phone by using sofware called,"My phone explorer.". because wen u will reinstall the software at that time ur phone memory will be formatted including ur phone book and sms.

Turn the device off and then back on.
Verify that the device's signal strength.
Attempt to place a call and connect to the Internet.
Attempt to write and send a new text message.