If you get the message "Cannot recognize one or more recipients or address is not valid" when trying to send a Text Message, and all of your numbers and addresses are correct, follow the below steps.

I have ever used Cucusoft iPhone Tool Kits to backup iphone SMS messages &contact to computer,you can free download in: HERE

Cucusoft iPhone Tool Kits is an easy to use utility designed to help you back up all your files on your iPhone, so that you can recover any lost or missing SMS messages&contacts,games,songs, videos, books, photos and so on.

Use guide:

Backup and recovery iphone SMS message and contact to computer

1. How to use Cucusoft iPhone Tool Kits to backup all iphone files to computer?
   
   Cucusoft iPhone Tool Kits is an easy to use utility designed to help you back up all your files on your iPhone.”
2. 
   
   
   “Cucusoft iPhone Tool Kits will quickly backup and transfer iPhone songs, videos, photos, SMS, call list, contacts and books to computer.”
   
   
   
   “From this window of Cucusoft iPhone Tool Kits you are allowed to change the backup folders.”
   
   
   
   “Cucusoft iPhone Tool Kits will also offer the possibility to create a subfolder rule.”
   
   
   
   Software Requirements：
   Windows 9x, Windows 2000, Windows NT, Windows XP, Windows Vista, Windows 2003 Server, Windows 7, etc.
   DirectX 8.0 or later.
   Hardware Requirements： MMX-enhanced CPU or more powerful
   512 MB RAM or more
   Any VGA card