Check whether the phone number you sent an SMS to is correct. In general, we recommend storing mobile numbers in international format (e.g. +352661xxxxxx) so SMS messages will be sent even when the person you’re contacting is abroad.
Some foreign operators may use a ‘hub’ to ensure messages are sent securely. Some settings may not be activated correctly with these operators and these users may not be able to send or receive messages.
If the recipient’s mobile phone is switched off or has no signal, the SMS message cannot be delivered.
You can choose to receive an acknowledgement of receipt in your phone settings.
For iPhone users, please deactivate iMessage.
If the problem persists, contact our customer services department on 606.