Troubleshooting Carrier Blocking

Like email providers, mobile carriers use advanced filtering systems to protect their subscribers from unsolicited spam messages.  If you've found that many of your messages are not being delivered to your recipients, it's possible that your message, or your phone number as a whole, is being blocked by carriers. 


Here are a few questions that may help you identify and correct the issue:

  • Did the blocked message contain "spammy" content?
    • Are you sending messages in ALL CAPS?
    • Did you send a message that sounds like a business promotion? (Marketing and business promotions aren't allowed on local or toll-free numbers.)
  • Did the blocked message contain a link?
    • If you are using a public URL shortener like Bit.ly or Tinyurl.com, that could be causing your messages to be tagged as spam. Try using our built-in URL shortener instead, or include the full destination URL in your message.
    • If you notice that messages that containing your MojoTxt short domain (i.e. mt01.org) are being blocked, please contact us and we'll switch you to a new domain.
  • Did you send messages to people who didn't specifically opt-in?
    • If so, they may have reported your messages to their carrier as spam.  Carriers take these reports very seriously and will block your number if they receive an excessive amount of reports. 
  • Are you sending an MMS to a large number of recipients?
    • Carriers filter MMS messages very strictly.  We recommend sending MMS to groups of less than 100 for the best deliverability.
  • Are you sending a too many messages over a local phone number? 
    • If you are sending more than a few hundred messages per day, we recommend switching to a toll-free number to send to larger groups. Carriers expect local numbers to be used by individuals, while toll-free numbers are cleared for high-volume messaging.


If none of the above suggestions correct the issue, it's possible that your phone number has been blocked from sending messages at the carrier level.  In this case, we recommend switching to a new phone number. Choose a toll-free number to decrease the likelihood that this issue would recur in the future. 


Still having trouble?

If these tips don't solve the problem, please reach out and we'll be happy to assist!