Apple's Messages app has a built-in safeguard to prevent links or phone numbers in unsolicited messages on iPhones from being ...

Spammers use your reply ... block spam. An app like RoboKiller, available for both iPhone and Android, can dramatically reduce the spam you receive, both in the form of phone calls and text messages.

Your iPhone allows you to block text messages from any number on your device in a few simple steps. You can block contacts already stored in your phone or unknown numbers not stored on your device.