You can receive a maximum of 2 SMS notifications in 30 minutes (total for attacks and espionage actions).
If you do not receive a message, it is often because this limit has already been reached. However, if you have not yet exceeded the limit and still have not received a message, then please note that SMS notifications are a function for which we can not guarantee. The successful delivery of an SMS depends on numerous factors (coverage of the mobile network, possible spam filters of your provider), which we can not influence. Ingame, in the General Status window, is also referred to this aspect.
And finally there is still the possibility to use the email notification, which is also offered exclusively to players with activated general status.