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E-mail to SMS being blocked due to suspected SPAM


I work for a trucking company, and we use e-mail to SMS to send out dispatch messages to our drivers for load information. Drivers can then reply to those messages to have conversations with dispatchers who operate via e-mail.

This has been working for years; however, as of 3/26/2018, it seems our entire domain has been blocked by T-Mobile servers. E-mails sent to xxxxxxxxxx@tmomail.net are rejected with 550 errors. I have tried sending as plain text, e-mail, short, long, with picture, and just about every way I can think of, but it's always blocked. Messages sent to all other mobile carriers are still going through just fine.

I have tried calling support, but no lower-level techs seem to even understand what E-mail to SMS is, and they just exhaustively try things that are specific to one individual phone. They supposedly escalate the issue, but we never hear back. I am desperately searching for someone within T-Mobile who can actually tell me why my domain is suddenly being blocked. This functionality is critical for our drivers to do their jobs; I'd prefer my answer to those drivers not be "sorry, find another carrier" as they keep asking us why their messages are failing while all the non T-Mobile users are moving along just fine.

@srickar​ - I've seen where you've been super helpful to some people; is there any chance you could help us out, too? I can PM you specifics.

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Best answer by tmo_chris 5 November 2019, 00:21

Hello folks,

I wanted to pop in here and update the correct answer as the rules and guidelines on automated SMS traffic have changed.

  • 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.

This thread is now locked and will be archived 11/9/2019

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234 replies

Userlevel 3
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There's plenty of these messages passing, except for De Soto. The issue is with sender policy framework because the IP is not permitted to send email on behalf.

meraki.com does not designate xxx.81.xxx.60 as permitted sender

Check the domain here.

https://kitterman.com/spf/validate.html

I don't own Meraki.com, it's Cisco's. Any chance we could just whitelist those for my mailbox? These alerts are important for me to receive. They worked up until about 2 months ago.

Userlevel 3
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You may be utilizing their service tools, but that doesnt mean they grant permission to send email using their domain envelope.

The issue is that the cosmetic envelope "from" is being misappropriated. So as a K-12 school, the envelope needs to stay as k-12domain.com, so the IP will match the originating source of the message. SPF is an industry standard to prevent envelope spoofing. SPF check is performed against the presented envelope against the DNS SPF entry. There are two version of SPF, hard and soft fail. We honor soft fail. If the envelope is corrected to match the k-12 domain, the messages shall pass.

Meraki has control of their DNS and reserves the right to control what domains can send mail on their behalf. They are broadcasting these as acceptable, and no other.

Found v=spf1 record for meraki.com:

v=spf1 include:amazonses.com include:servers.mcsv.net include:_spf.google.com include:_spf.salesforce.com include:mktomail.com ~all

Hi srickar, I have seen that you've successfully helped lots of T-Mobile customers with this problem. I've sent you a follow request - please let me know how I can be helped as well!

I've always had my email's forwarded to my tmomail.net address, which then came through to my phone (albeit sometimes missing content, but it at least worked as a notification). for several years now, though, many of my emails no longer go through, especially from The Weather Channel and the NYC DOT (but not limited to them).

I'm not particularly technologically inclined, so if you could tell me what I need to give you to enable you to help me, that'd be great.

Thanks in advance.

Userlevel 3
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I can certainly help you. Please send me a follow request and/or accept the request from me. You can then send me a PM and I can investigate.

Srickar, I’ve sent a follow request to you. It seems that messages being sent by our companies automated systems are being blocked by T-mobile. We send alarm messages from critical medical equipment and critical research facilities . Our email server is located in Germany (Siemens.com) and hope to get it whitelisted. Thanks in advance.

Userlevel 3
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I have reviewed similar issue before. Siemens.de is sending email messages routing towards north america. We are blocking .de TLD domain because of the preponderance of spam targets from that domain TLD thinking they are spamming us through parent company Deutsche Telecom. Spammers are forging the cosmetic address for siemens.de and unfortunately I cannot unblock this without also allowing a flood of actual spam content. Due to the minimal need for international based TLD's to communicate with north american long 10 digit email addresses, the messages are not accepted.

Is there any solution for this on the TMobile side?

Dwane Miles

Userlevel 3
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Due to sending SMTP server originates from .de TLD the message will not pass.

Hi srickar,

I'm also having the same issue as these other users. I have attempted to test email to SMS from my O365 account, but I receive a bounceback stating that tmomail.net suspects it as SPAM. What do I need to do to whitelist my domain?

Thanks,

Bryan

Userlevel 3
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Please send me a follow request so you can send me a PM. Outlook failure messages are always too vague.

Hi srickar,

I have sent a follow request a few days ago, but it still shows 'Awaiting Approval'.

Thanks,

Bryan

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I have accepted it. Can you send me a message now?

Still unable to send.

Userlevel 3
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Not sure if this is a bug. From my view, it says "waiting approval" from you to accept my connection. Make sure its the message connection.

Although that error is present, you can try and continue to submit the message as messages will sometimes send anyway.

I did approve the connection and it says we are connected. I did attempt to send you two messages, which it said sent.

-Bryan

Hello,

I am having the same issue as others where my email forward from Gmail to tmomail is being blocked. I requested to follow you so you can help me get whitelisted on the sms gateway.

Please let me know once we can proceed via PM.

Thanks!

Userlevel 3
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You got it! I sent you a follow request.

@srickar​ I am having the same problem, can you please help me too.

I have open many ticket with support but they keep closing the ticket without notifying me.

One of the ticket # is 24180443 and another one was 22811627.

Userlevel 3
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I sent you a follow request. Please review all SMTP rejection errors for clues on reason. SPF Sender Policy Framework is the most common.

Srickar,We checked all the policy and they are all working.  SPF on the outgoing server is valid.We can send email/SMS everyone except to all t-mobile SMS, email to AT&T SMS and Verizon SMS work fine.  Only t-mobile does not work.Also we can email to anyone including support people from "xxxxxxx@t-mobile.com" the problem is just with "xxxxxxxxx@tmomail.net"

@tmomail.net is blocking our domain "@enigmasoftware.com"  Can you please have someone higher in the support chain to unblock us.

Our problem is exactly the same as https://support.t-mobile.com/thread/144851t-mobile was able to unblock the person in the above link, we just need t-mobile to do the same to unblock "@enigmasoftware.com"

This is the response from tmomail.net"550 permanent failure for one or more recipients (6463796888@tmomail.net:blocked) "

Thanks,Kok Leung.

On Monday, August 5, 2019, 04:57:44 PM EDT, srickar <no-reply@t-mobile.com> wrote:

#yiv0340212121 * #yiv0340212121 a #yiv0340212121 body {font-family:Helvetica, Arial, sans-serif;}#yiv0340212121 #yiv0340212121 h1, #yiv0340212121 h2, #yiv0340212121 h3, #yiv0340212121 h4, #yiv0340212121 h5, #yiv0340212121 h6, #yiv0340212121 p, #yiv0340212121 hr {}#yiv0340212121 .yiv0340212121button td {}

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T-Mobile Support

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E-mail to SMS being blocked due to suspected SPAM

reply from srickar in Network & coverage - View the full discussion

I sent you a follow request. Please review all SMTP rejection errors for clues on reason. SPF Sender Policy Framework is the most common.

Reply to this message by replying to this email, or go to the message on T-Mobile Support

Start a new discussion in Network & coverage by email or at T-Mobile Support

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Userlevel 3
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As stated previously and from checking the domain, the underlying cause is Sender Policy Framework. Your DNS administrator has specifically restricted the domain to very specific list of IP's allowed to send on behalf of your domain.

@enigmasoftware.com does not designate 209.85.166.47 as permitted sender

That IP belongs to Gmail/Google Mail.

Please visit https://www.kitterman.com/spf/validate.html  and insert enigmasoftware.com in the search box. The SPF record as published does not permit 209.85.166.47 as an authorized IP source to send on behalf of the domain. And the reason that is, is because a Gmail user (which appears to be what is being used here), cannot manipulate the outgoing reply-to envelope to display as enigmasoftware.com (That is forgery). The reply-to envelope is checked against SPF DNS, and when a record is published restricting such action, it is honored.

Received: from mail-io1-f47.google.com (mail-io1-f47.google.com [209.85.166.47])

Userlevel 3
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Hi @magenta9532622

I checked and see the SPF DNS has been updated to include google in addition to the initial ISP. I also see a passing message.

Can you confirm if the issue is resolved?

SPF records are published in DNS as TXT records.

The TXT records found for your domain are:

v=spf1 include:sendgrid.net include:_spf.google.com ~all

MS=ms77576903

Hello,

I am having problems with an email address associated with automation system at work.

Please friend request me

thank you

Hi,

We have an application that churches use to communicate with people in their church.  They can send text message for things like volunteer scheduling requests and reminders and weather related cancellations etc.  The email is coming from @churchteams.com and we have a great email reputation and use SPF, DKIM and other email best practices and our E-mail to SMS messages to other carriers are going through fine but T-Mobile users are not getting them as it seems our @churchteams.com domain is blocked.  Below is an example of the returned message (with the person's phone number removed so it's not posted on the forum).  This is happening to multiple churches since they are sending from the @churchteams.com domain name and so I'm hoping to get @churchteams.com whitelisted as others have in this forum so let me know how to proceed or if you need more information etc.

Bounced

550 permanent failure for one or more recipients (xxxxxxxxxx@tmomail.net:blocked)

2019-08-19 3:30:08 PM

Thanks so much for your help!

Mark

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