Steps and specific guidelines to reduce the risk of messages being filtered
Updated: October 28, 2024
Message filtering refers to the blocking of messages that are unwanted or illicit. Filtering may occur to enforce or to comply with regulations and wireless carriers’ messaging policies.
Consent and opt-in
- Ensure that you only send messages to mobile users who have provided consent (opted-in) to receive messages from you.
- Ensure that your messages clearly identify who is sending the message, and how to opt-out. If you are contacting the same recipients multiple times per month, you do not need to provide opt-out instructions in every message, but you must do it at least once per month.
- The opt-out language you include in your messages must include a widely accepted keyword for opt-out. In the US and Canada this is typically STOP, e.g. "Reply STOP to unsubscribe." Using alternative phrases like "text 2 to opt out" is not compliant, and will result in filtering.
- If you are sending messages to users repeatedly over a long period of time, you should check in with your recipients at least once every 18 months to ensure they still want to receive messages from you. The mobile number you are sending messages to may have changed owners, or the recipient may not remember giving consent to receive messages from you.
- You should process the DNDs daily. Once a customer deactivates their phone number, you no longer have consent to send to that number.
- Monitor your opt out, and consumer complaints data for any spike in activity. This is an indicator that there is something that needs corrected in your consent or opt out mechanisms. Carriers will start filtering heavily, or completely block traffic as phone numbers receive complaints/high opt out rates.
Use case and sender selection
- Check the SMS Guidelines for the countries you are sending messages to.
- In general, use only as many phone numbers as are required for your business. Phone Messaging Policy forbids "snowshoeing" message sending across multiple phone numbers for the purposes of evading message filtering systems.
Message contents
- URL shortening: Do not send links that have been shortened using shared public URL shorteners, such as TinyUrl or free Bitly links. United States carrier policies discourage the use of shared public URL shorteners
- If possible, when sending URLs/links in your messages, use domains that you control. Similar to the shortened URL guidance above, when sending links it is best to use a URL that is specific to your business.
- Don’t use emojis, or unnecessary special characters/capitalization, and watch your grammar and spelling. Typically, these messages are structured in a way to attempt to evade detection of unwanted messaging, and your messages will be filtered.
I think my messages are being filtered by mistake. What can I do?
- No automatic system is perfect. If you have reviewed the above information thoroughly, and you believe your messages are compliant, please grab 3 or more examples of the Contact example links that have the “undelivered” status with error 30007 within the previous 7 days and share it with our team so we can troubleshoot further.
- We can help review your messaging and determine if an error was made
- For more information on message filtering, see How Does Message Filtering Work?