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What is SMS Filtering & How does it work?
What is SMS Filtering & How does it work?

Everything you need to know about SMS Filtering and how it works and what you can do to mitigate it.

Jack Kennedy avatar
Written by Jack Kennedy
Updated over 10 months ago

This guide elaborates on SMS filtering that may impact the delivery of your Whippy Programmable SMS messages, aligned with Whippy’s Messaging Policy or Acceptable Use Policy, and in compliance with regulations and wireless carriers’ messaging policies.

Filtering of your outgoing Whippy Programmable SMS messages can differ between carriers and countries. This guide is designed to help you understand why a message might have been filtered and how to minimize the risk of your messages being flagged as spam.

Why do message filtering systems exist?

Message filtering systems serve two primary purposes:

  1. Protecting Mobile Subscribers: To safeguard users from spam, fraud, or abuse, which can lead to serious consequences, including fines or disconnection by carriers.

  2. Enforcing Messaging Rules or Regulations: Different countries have varying restrictions on messaging types, and messages violating these rules may be filtered.

How does message filtering work?

Message filtering varies from basic lists of prohibited terms to complex machine learning systems. Whippy employs filtering to address messaging that violates our Messaging Policy and Acceptable Use Policy (AUP), ensuring compliance with carrier and regulatory rules.

Preventing Your Messages from Being Flagged as Spam

To reduce the risk of your messages being filtered:

  1. Target Willing Recipients: Only message those who have shown interest. Preferably use double opt-in methods to confirm their willingness to receive messages.

  2. Provide Opt-Out Options: Include a clear method for recipients to opt out in your campaign messages.

  3. Personalize Your Messages: Use your name and the recipient's name in your campaign messages.

  4. Avoid Sensitive Content: Steer clear of references to drugs, alcohol, gambling, or hateful content.

  5. Simplify Your Messages: Keep messages concise and free from emojis and special characters.

  6. Don’t Resend Blocked Messages: Repeatedly sending a blocked message can lead to further blocks for "Velocity SPAM."

  7. Maintain Compliance on Your Website: Ensure your website has a valid terms of service, privacy policy, and appropriate opt-in settings.

How do I know if my messages are being filtered?

Messages typically show the “Undelivered” status when filtered. However, it’s not always possible to determine when a carrier has filtered a message.

Why am I charged for filtered messages?

Filtered messages are billed to cover the costs of running effective filtering systems and the expenses incurred in sending the message to the carrier.

What to do if your messages are being filtered mistakenly?

If you suspect legitimate messages are being filtered, collect examples of Conversation IDs with the messages that have an “undelivered” status and contact Whippy's Support team for assistance.

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