Text Delivery

What are Carrier Filters?

In the past decade, bulk text messaging has become the holy grail of marketing due to the amazing results it produces. However, not all mobile users like to receive marketing messages so it was only a matter of time before filtering would kick in. And not only did it kick in but it seems like the filtering is getting stricter each week, or even each day. In this article, we will explore the issue of carrier filtering and try to give you some tips that will help your campaigns fare better in the ‘filtered water’.

Why are text messages being blocked or filtered by carriers?

As mentioned above, most people don’t like to receive unsolicited messages or spam texts. When they do, they complain to their carriers and the carriers respond by filtering out those messages for other recipients as well, sometimes even greylisting or blacklisting the source number. This is because carriers have a high cost for dealing with complaints and a large amount of traffic coming in from spam messages. In fact, it is cheaper for them to invest millions of dollars per year in people and software with the sole purpose of blocking spam messages (which sometimes are not even spam).Also, if you are using a 10-digit local phone number to send mass messages, it is quite probable that some of your messages will be filtered and will not be received by the targets. In this case, it doesn’t matter if they are solicited or not - phone carriers are not reviewing your opt-in lists, they are monitoring the volume and frequency of messages, along with the content check. 

How to know if text messages will be blocked or not?

Carriers reserve the right to block specific kinds of messages or numbers. The tricky part is that what is considered ‘specific’ is an ever-evolving set of criteria that is kept hidden. On the other hand, filtering systems can be really smart and advanced, so each day will be a little bit harder to bypass them. Carriers can also quietly discard texts classified as spam without any further notice, while still returning a successful delivery status for them (making it a bit harder to know that you are being blocked or that the messages were not delivered).  

Can I avoid being filtered or blocked by carriers?

If you follow some basic guidelines you can definitely reduce the chances of being blocked.

When sending texts, keep in mind that you should:

  • Be as short as possible.
  • Include a call to action that generates replies to your number. If you can make your targets reply to the message, this will help a lot.
  • Avoid unnecessary capital letters.
  • Refrain from using any aggressive language.
  • Include an opt-out line so that people don’t have to call their carrier to block the number

Also:

  1. Make sure to have permission to text before sending messages. People who didn’t opt-in are more likely to opt-out and higher instances of people unsubscribing can also raise flags with carriers.
  2. If you are sending a lot of texts per campaign have texts slowly drip (no more than 20-30 per hour)

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