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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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233 replies

Srickar,

My company is thinking about changing our FROM domain to one ending in “.email” as the domain suffix (top-level domain). Because that is the only other domain we have registered, and we need to shorten our FROM addresses for various reasons.

Do you think that “.email” will face SPAM problems with TMobile (and other recipients)?

Userlevel 3
Badge +3

.email TLD is okay to use. For example, https://gaggle.email/ is in use. It's the two character TLD international types that are likely blocked because of preponderance of spam from those sources. With ICANN's increase in available TLD choices, spam has increased and never know if a domain will be "memorable" enough for contacts and mistyped emails as most may default to .com, etc. Good luck in the transition.

@srickar

We are also getting 550 errors when sending emails to the *@tmomail.net addresses. Not always, but quite a bit of our emails are getting bounced back. I sent you a follow request. the domain they are coming from is alarminfo.net

Userlevel 3
Badge +3

Certain messages are failing because there is likely a few servers added that are missing configuration parameters such as system timestamp date and message-ID.. For example, one of the examples not sending over message-ID in the header, which is needed to prevent high spam scoring. Messages that are passing properly have all this included. Also, messages are sent in ALL CAPS, which increases score value.

A message ID looks something like this: Message-ID: <5dbc935e.jbOKy92mzMmaM9q/%@alarminfo.net>

Rule breakdown below

pts rule name description

---- ---------------------- --------------------------------

1.40 MISSING_DATE META: Missing Date: header

0.30 TVD_RCVD_SINGLE HEADER: 

0.14 MISSING_MID META: Missing Message-Id: header

0.00 NO_REAL_NAME HEADER: From: does not include a real name

0.01 SUBJ_ALL_CAPS META: Subject is all capitals

1.62 SUBJ_ALL_CAPS_2 META:

Hi @srickar,

I found this thread and wanted to add issue I recently ran into.  I'm using camelcamelcamel (amazon price tracker) to send email alerts to my gmail account.  I setup a gmail filter to forward these emails to my cell phone via the tmo email SMS gateway.

This worked fine for 1-2 weeks but then it stopped working and getting:

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

Emails are coming from noreply@camelcamelcamel.com

Also sending manual email from my gmail to tmomail is getting blocked too.  If I send from yahoo email it works fine.   Please help, thanks.

Userlevel 3
Badge +3

Thanks for bringing that to my attention. I have resolved the issue with gmail.

Camel is a great tool for sure!

Userlevel 5

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

Badge

Hi @srickar,

 

I found this thread and wanted to add issue I recently ran into.  I'm using camelcamelcamel (amazon price tracker) to send email alerts to my gmail account.  I setup a gmail filter to forward these emails to my cell phone via the tmo email SMS gateway.

 

This worked fine for 1-2 weeks but then it stopped working and getting:

 

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

 

Emails are coming from noreply@camelcamelcamel.com

 

Also sending manual email from my gmail to tmomail is getting blocked too.  If I send from yahoo email it works fine.   Please help, thanks.

I am having a similar issue. I have my gmail account to forward emails of certain in stock items from 3 websites. Just received notification that the email account was blocked by tmomail.net

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