Mobile subscribers add Premium Messaging block on their wireless account to block any content from a shortcode (5 to 6 digit number used by commercial SMS traffic).
Although intention is to block the Premium content (ringtone download; subscription service such as horoscope, weather, sports scores, songs, wallpapers, etc.) which uses reverse billing by wireless operators (they collect $20 from the subscriber, take 30% cut and transfer the fund to the Premium content provider); unfortunately,
it also blocks Standard message content (text messages from a 5 to 6 digit number).
Four US major wireless operators do not accept Premium content campaigns and will be discontinued by other wireless operators shortly.
Removing the Premium Message block feature from your (end user) account will allow standard messages to be passed through. If you (end user) are uncomfortable removing the Premium Message block, you (end user) can whitelist a shortcode with the wireless operator. In this case, content from a shortcode (e.g., 35842) will get delivered to the mobile device.