AT&T and Verizon have increased their message filtering aggressively towards messages containing URLs. While our team is actively engaging these mobile operators to communicate that these are opt-in messages the end users subscribe, so far AT&T and Verizon have not made a commitment to address this issue. Based on the data, monitor and flag certain trigger words or phrase that causes your message to be blocked. 

Current Recommendation

When copying and pasting your links for group messages, replace https:// or http: with www. (make sure to include the ‘.’). 

e.g. Instead of sending use 

Links that include https/http are one of the flags that Verizon and AT&T are checking. They see this as something a regular person would not do. Most people will say, check Google or Search They are likely not going to say 

The reason we are asking you to add www. is to ensure when your link goes out via text, the phone recognizes it as a link. 

That means, if you have a link to your website, e.g. remove the http, add or leave the www., test that it still works (some websites don't work with the WWW), then send that instead. So, you will send via PastorsLine. 

If (or an external link like MailChimp newsletter or a ChMS form link) does not work for your website (the DNS of some websites isn't setup to work with the WWW), we recommend using is like but more powerful and new to the market. is used a lot and we believe it's also being flagged by the carriers if they see the same link in multiple messages from the same local number over a short period - basically, sending a group blast. is free to use and has some cool options to personalize your domain name. We plan to integrate with this option in the future but for now, add your link to your free account. Same process, use This option will work great to send traffic to any link. Bonus, you get click stats as well. 

Override and Send Anyway

However, it may be that you want to send a text 'as is' anyway, taking your chances. In general, and especially for large groups of 100 or more, we strongly recommend using secondary numbers. For smaller groups, sending such texts might succeed.

We decided to let you make the call. So, you can now override our recommendations and 'Send Anyway'. 

We will record your decision so that in case there is an issue with the text delivery, we will be able to more accurately understand what happened. Below is how your 'sent anyway' text will look in your logs.

More information

Why do carriers have content and spam filters?

When subscribers receive messages they find objectionable, they may file complaints or report the carrier to governing bodies, seek damages, or simply stop being a customer. All of these things reduce the revenue of or increase costs for carriers. Thus, it is in the best interest of carriers to protect their subscribers from what they consider to be objectionable content.

How do carriers filter messages?

There is no standard practice for carrier filtering across all carriers. For some, filtering can range from a simple static list of prohibited terms to advanced machine learning systems that work in real time. Regardless of the system, carriers keep their filtering systems closely guarded secrets. In turn, PastorsLine cannot say definitively how these systems work or why a particular message was filtered.

How do I know if my messages are being filtered?

PastorsLine does not always know or predict when a message has been filtered by a carrier. Some carriers falsely report filtered messages as delivered to prevent spammers from reverse engineering filtering systems. In other cases, carriers will tell PastorsLine that a particular message has been filtered.

How do I prevent my messages from being filtered?

If you see an increase in carrier filtering you messages, these questions provide some general guidelines for sending messages:

  • Is it a good user experience?

A confusing message to users might seem like someone they don’t know has their contact information. Suspicious users are more likely to report messages to their carrier, and when messages are reported to carriers it becomes very likely that future messages from that number or with similar content will be filtered. In some cases, the user may have forgotten that they requested the message. Also, how the message is formatted and written is important: overly long messages, overly capitalized messages, mysterious links, hyperbole, and using aggressive language can raise the level of suspicion users feel about a message.

  • Do users have clear opt out instructions?

If users do not understand how to opt out, they may feel they have no choice but to contact their carrier to request that messages are blocked.

  • Is a single number being overworked?

In countries where rate based filtering takes place, sending too many messages from a single phone number or alpha sender ID during a time period could cause that phone number or sender ID to be blacklisted.

United States and Canada filtering

Filtering Mechanisms

Carriers in the U.S. and Canada appear to be using adaptive (machine learning) software systems to protect their users. These systems take into account both the rate of send, as well as the content of the messages and behave very much like email filtering systems. Messages receive a cumulative score based on how many messages have come from a phone number during a time period, how many similar messages have transited the carrier’s network, or if the message contains content that makes it a high match for spam. Time periods are measured by the second, minute, hour and day.

PastorsLine does not definitively know how many messages can be sent from a long code before a user can expect to hit a filter. However, we highly recommend following the guidelines mentioned in Messaging Principals and Basic Practices published by CTIA in Jan. 2017, where CTIA suggests that Application-To-Peer (A2P) Messaging that’s “consistent with typical human operation” should be expected to be deliverable across the messaging ecosystem. Some key attributes of typical human operation include:

Carriers in the US sometimes report to PastorsLine when a message has been filtered. If you suddenly see that a large number of your messages are resulting in a status of “Undelivered” with a 30007 error, the carrier has taken some sort of action which has caused your message to be filtered.

Message Delivery in the United States and Canada

I think my number has been blacklisted by a carrier. Can I get it removed?

No. However most blacklists in the US and Canada use a “cooling off” period, which means that most numbers will automatically be removed from the blacklist after a period of time. This period of time varies based on how many messages were blocked by the carrier from this number, and carriers do not share this time period with us.

Can I get my messages whitelisted by the carriers?

US Carriers do not whitelist messages from long code numbers. Short codes are essentially numbers which have been whitelisted for a particular type of pre-approved traffic. If you are sending many messages with identical content to a large number of users, you are at high risk of having your messages filtered by carriers and should consider a short code.

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