Sendgrid being blocked


    X-SendGrid-QueueID: 561860164

    X-SendGrid-Sender: <>

    Arrival-Date: 2019-12-06 19-58-21


    Final-Recipient: rfc822;

    Original-Recipient: rfc822;

    Action: failed


    Diagnostic-Code: 550 permanent failure for one or more recipients (




    I've replaced the phone number with x's


    Our company uses Sendgrid to send information to clients, recently they've been getting this bounce-back when emailing to text.


    What do I need to do to get these cleared through?


    I'm aware of these rules:

    Per Cellular Telecommunications and Internet Association (CTIA) Industry guidelines, Intercarrier guidelines and T-Mobile's own Terms and Conditions of Service, automated commercial SMS traffic routing on any network should use short codes.


    Repetitive mass texts over 10-digit texting are forbidden by CTIA carriers, including T-Mobile. Continued SMS abuse can result in subscriber number being permanently blocked not only by T-Mobile, but also by other carriers, which is outside of T-Mobile control.


    Commercial trafficking is only allowed through short code, and not through long code (10-digit numbers) and a customer must opt in to receive content.


    Third-party services can send bulk messages, but such vendors are unaffiliated with T-Mobile.



    But that last line suggests that Sendgrid should be able to transmit these messages properly.


    We need to be able to send these messages, what can I do? Thanks in advance!

      All replies