There are many of users reported that they can't send text to the android users which is a very frustrating problem that every iOS user faces. Fortunately, there is always a solution to every problem. In this forum we have come up with the methods that you can follow to get rid of the iphone not sending messages issue.
1. Check the device settings
2. Check recipient number
3. Restart your iPhone
4. Update your iPhone software
5. Reset network settings
6. Deregister iMessage
7. Contact your Carrier