E-mail to SMS being blocked due to suspected SPAM

Show first post

234 replies


I am having the same problem.  We are an alarm company where our alarm panels send out email-to-SMS messages to our customers.  T-Mobile is now blocking 550 our emails.  We need to get our domain white listed as well.  I opened a support ticket, # 25596751, today by phone, but they really didn't seem to understand my problem.  I'm really hoping to get white listed as our customers with T-Mobile can't receive any alarm notifications right now.  All other carriers receive the messages without any problem.


Userlevel 3
Badge +3


Id like to look into this further. I could not locate a sending domain to the # listed in the ticket. Can you please follow me back through inbox and send me a direct message? Thanks.

Hi @srickar,  I'm having the same issue as everyone else.  I sent you a follow request.

Userlevel 3
Badge +3

Hi @hiddensoundhostel

That issue is quite different from other examples. In this case, double relay forwarding is not permitted because proxy forwarding of spam also utilizes this method. The purpose of double forwarding allows for spamming entities to circumvent direct detection using webmail providers that cannot be outright blocked. If sent directly, the messages will pass.

I am having the same issue - can you assist? I sent a message - maybe I am not doing this correctly - but I sent this message -

Hello! We are having the same issue and could use some help with this. I was able to receive email to SMS on my tmobile device until just recently. I was testing a new service we intend to provide to our customers as we have an online auction site and customers would like to sign up for a outbid notification. Please note that they have to sign up for this service. We can send to ATT and Verizon and other carriers but get this bounce back from Tmobile.

The email is coming from an

    host []

    SMTP error from remote mail server after end of data:

    550 permanent failure for one or more recipients ( rejecting banned content
We will try changing the from / sender email and see if that helps - if not what do we need to do to get our domain white listed?

Try using something besides<>. Info, Webmaster, Postmaster are blocked because of spam.

Hi @srickar​, I changed it so my email account forwards the email directly to my phone via text message (instead of forwarding the email to another email account that then forwards the email to my phone via text message).

I'm getting this message now:

"Message blocked.  Your message to [my number here] has been blocked. See technical details below for more information. 

The response from the remote server was:  550 permanent failure for one or more recipients ( [my number here] rejecting banned content)"

Is there something else I need to do?


Userlevel 3
Badge +3

Send me an inbox follow request and I can investigate more closely. Thanks.

@srickar​   How can I get a message to you - I have the same issue?

@srickar​ my team wanted to know if it were possible to add a particular whitelist our domain for the survey or sending email address that flag our email? 

Userlevel 3
Badge +3

No sorry, cannot whitelist external entries. The reason certain messages are blocking is due to sending out survey links for .us TLD. This is a common spamming tactica which these messages are similar. This type of solicitation ideally should be routing over a subscription shortcode based service as these emails are sending out solicitation asking recipients to click links.

I think I sent the inbox follow request, but I don’t see a way to send you additional informantlion.


Not sure if you did anything but everything now works with forwarded emails to SMS from Thank you.


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, 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.


We are also getting 550 errors when sending emails to the * 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

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/>

Rule breakdown below

pts rule name description

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

1.40 MISSING_DATE META: Missing Date: 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


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 (

Emails are coming from

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 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

Userlevel 5

Hey, @ffit37129​!

I've seen an uptick in situations such as yours. It's possible that your company's domain just needs to be whitelisted. While I don't have the answers to why the sudden change, there is a ticket that can be filed. I know you've already worked with our tech support a few times with no luck.  Do you happen to know if a ticket was previously filed?

Yes, I do have an existing ticket. The number is 19367035. Thanks for your help!

Userlevel 5

Thanks for the handy info, @ffit37129​! I just sent a private message your way to provide more info. You can check your inbox here.

Thanks for that info, but that did not work. We have verified our SPF policy on the outgoing mail server is valid and even tried routing through a totally different server, but we are still being blocked and have no idea why. I have not heard back from tech support.

Just to clarify, I can send the exact same message to my personal gmail account, and the gmail e-mail headers clearly state that SPF passes and that the sender is designated as permitted.

Userlevel 5

Thanks for getting back to me. It sounds like we need to whitelist the domain. The only way to do this is via tech support or T-Force (Facebook/Twitter) and you'll need to refer them to doc# 433442 on steps with how to file the ticket.