HowTo: fix Android "Message not sent" problem

Do you immediately received a "Message not sent" notification after trying to send any text message? Try this to fix the problem of an Android phone refusing to send text messages despite being able to receive them.

1. Open the phone dialler and type in the following:  *#*#4636#*#*

   

   Add the SMS Center number

2. A menu should appear, select 'Phone Information'
3. Scroll down to find the empty box named "SMSC:"
4. Discover the SMS message centre number for your mobile provider:
• Either search the internet, e.g. "O2 UK SMSC number"
• Or look it up in a list such as this one: http://smsclist.com/downloads/default.txt
5. Enter this number in the box and click update
6. Press the back button to exit these menus
7. You should now be able to send texts!

I had the problem on a HTC Nexus One running Android 2.3.7, Cyanogenmod 7.1.0-N1 although it may affect other configurations.

Hopefully this helps, let me know in the comments if it fixed your problem!