Unable to send sms to groups abroad

Hello,

I'm creating an app that allows me to send sms to groups and abroad. Im facing a problems when sending to a group that contains iPhone and Android devices from different countries resulting in the message not being sent.

Here is what I'm doing to create the text messages:

let messageVC = MFMessageComposeViewController()
messageVC.body = "body message"
messageVC.recipients = ["+123456","+123456"] //numbers with country code and area code
messageVC.messageComposeDelegate = self;
if MFMessageComposeViewController.canSendText() == true {
     self.present(messageVC, animated: false, completion: nil)
}else{
     //displays error message
}

This presents the composer for SMS/iMessages, but when the sent button is tapped it looks like the message will be sent but at the end none of the messages are sent and a red "Not Delivered" message appears.

If I try to send the message only to iPhones and locally it works.