blocking messages




    My home automation system sends me SMS messages using T-Mobile's email to SMS gateway.  I have been using it successfully for a number of months, but recently, my messages have been blocked.  I have included a sample rejection notice below.  Does anyone know precisely why my messages are being blocked all of a sudden and how to get around this?


    Thanks so much for your help.



    Error Icon

    Message blocked

    Your message to has been blocked. See technical details below for more information.

    The response was:

    550 permanent failure for one or more recipients (


    Final-Recipient: rfc822;

    Action: failed

    Status: 5.0.0

    Remote-MTA: dns; (, the

    server for the domain

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

    Last-Attempt-Date: Fri, 01 Sep 2017 19:15:53 -0700 (PDT)


    ---------- Forwarded message ----------

    From: Home Automation System <>

    To: "" <>



    Date: Fri, 01 Sep 2017 20:11:32 -0600

    Subject: <message subject>

    <message body>

      All replies

      • j.a.r.v.i.s

        Re: blocking messages

        Looks like the email was blocked intentionally magenta2540820 - There are a few similar threads - check them out and post back if you don't get anywhere...


        email to sms gateway issues


        email to rejected for banned content

        2 of 2 people found this helpful
          • magenta2540820

            Re: blocking messages

            Thanks for your reply.  I looked through those posts, but couldn't find an answer.  I'm using gmail SMTP to send my email and Gmail seems fine with my authentication/authorization.  When I look at the headers of the email, it passes SPF, DKIM, and the other checks mentioned in those posts.  I'm not sure why my emails are being blocked all of a sudden and what the rules are that I need to follow for them to work successfully with the service.  Thanks again for your help!

              • j.a.r.v.i.s

                Re: blocking messages

                From what I read, it appeared that there was some learning/training to identify good/bad inbound messages.  Since it's something on the backend, probably out of scope for a customer facing support portal.  Did you try the enterprise support that was referenced?  Wonder if any of the @tmo_ users can comment...

                • tmo_amanda

                  Re: blocking messages

                  Hey, magenta2540820!


                  I'm not sure why it stopped all of the sudden, but as j.a.r.v.i.s mentioned, you aren't the only one this is happening to. I just chatted with one of our Engineers regarding this and here are a few things he recommended trying:


                  • If you're a DIGITS user, we recommend installing the app on your phone. Messages are successfully being sent and received through the app.
                  • If there's an option for the email to be sent via HTML format, it should force the email to stay as MMSC. I know this option isn't always available especially if it's coming from a larger company such as your home automation system.


                  If neither of these workarounds work, the next step would be to contact Tech Support and file a ticket with them. The more tickets that are filed, the easier it is for our Engineers to determine why this is happening.

                    • magenta2629596

                      Re: blocking messages

                      Having same problem. Started last week.


                      This message was created automatically by mail delivery software.


                      A message that you sent could not be delivered to one or more of its

                      recipients. This is a permanent error. The following address(es) failed:



                          host []

                          SMTP error from remote mail server after end of data:

                          550 permanent failure for one or more recipients (



                      I've had no problems for many years....except when sending a url. I have to remove http.

                        • dtmgallagher

                          Re: blocking messages

                          I am getting the same message as of last week and reported it to Tmobile support but they do not have an answer yet the very same barracuda network device is associated with Tmobile.


                          This is part of what I get back as being blocked.



                          Remote Server returned '< #5.0.0 smtp; 550 permanent failure for one or more recipients (>'

                          Original message headers:

                          Return-Path: <>

                          Received: from (localhost [])

                          by (Postfix) with ESMTP id 3zQDgr04l1z2hsWBB

                          for <>; Mon, 22 Jan 2018 14:43:20 +0000 (UTC)

                          X-USANET-Received: from [] by via mtad (C8.MAIN.4.10L)

                          with ESMTP id 598waVoro4736Me4; Mon, 22 Jan 2018 14:43:14 -0000

                  • deansongs

                    Re: blocking messages

                    Started failing for me two days back.  But, I had not used it in a while, so I cannot say when the problem *would have* started for me.  That said, all fail, to all addresses, from all email accounts/servers.  Also, I tried plain text and html.  Nothing in this thread is pointing in the right direction for issue I am seeing.  Is it working for anyone?  I am curious because I would like to use it, but have no huge need so I am not putting in a ticket.  Thanks to anyone for any help .