Filtering of your outgoing Grayscale SMS messages can vary somewhat between carriers and countries. We have compiled the following information to help you understand why a message might have been filtered 🚀
Why do message filtering systems exist?
Message filtering systems exist for two reasons:
Protecting mobile subscribers from unwanted messaging such as spam, fraud, or abuse
Unwanted messaging is a huge issue in the messaging industry; unwanted messages can result in complaints, fines, or outright disconnection by carriers. Mobile users who receive lots of spam or other unwanted messages may decide to start opting out of or ignoring all messages from businesses, even legitimate ones who follow all rules and best practices.
For these reasons, it is in everyone’s interest – Grayscale, wireless carriers, regulators, and most importantly our customers – to ensure that unwanted messaging is not allowed over Grayscale's carrier connections.
Enforcing rules or regulations about what types of messaging are allowed to that country or mobile network
Depending on the country, laws or regulations may put restrictions on certain types of messaging, or even forbid certain things altogether. Messages which violate these rules may be subject to filtering.
These rules and regulations may also change over time. In the U.S. and Canada, application-to-person (A2P) type messaging was historically not allowed to be sent using local 10-digit long code phone numbers. In 2021, however, U.S. carriers have launched the A2P 10DLC solution which permits A2P messaging via long code to United States recipients.
For information about the A2P 10DLC changes by U.S. carriers, see United States A2P 10DLC Registration.
How does message filtering work?
Message filtering can range from a simple static list of prohibited terms, to advanced machine learning systems that constantly adapt based on the messages passing through them.
Twilio, our third-party provider, uses filtering to target messaging that is in violation of their Messaging Policy and Acceptable Use Policy (AUP). Twilio’s goal, and in turn Grayscale's, is to protect mobile users from fraud, spam, and other forms of unwanted messaging, as well as to comply with rules and regulations imposed by carriers and regulators.
In addition, carriers filter messages to enforce their rules, as well as to prevent spam and other forms of abuse.
How do I know if my messages are being filtered?
When we know that filtering has taken place, you will see your messages with the “Not delivered” status and Error 30007.
It is not always possible to know for certain when a message has been filtered by a carrier. In rare cases, carriers may falsely report filtered messages as “delivered” to prevent spammers from reverse engineering filtering systems.
If Twilio knows that a message has been filtered, we will pass this information to you by updating the message status to Undelivered, and flagging error code 30007.
How do I prevent my messages from being filtered?
In short, follow the guidelines in Grayscale's Messaging Policy and avoid sending spam or fraudulent traffic. Keep your Grayscale account credentials secure to avoid account takeovers by malicious actors.
I think my messages are being filtered by mistake. What can I do?
Reach out to Support if you think your messages are being filtered by mistake – use the chat bubble below to send us a message or via email. Be sure to include the following information:
Screenshots of the filtered message
The recipient's phone number
Date(s) and time(s) the message was sent
Have questions? Chat with us below!