my sms messages blocked as spam  - from a prospect to me -   support says buy a shortcode $$$$$$

I had important text messages get blocked by T-mobile.  I get  robo phone calls all day long. Not received a single spam sms ever and they blocked my SMS  sent by a customer to my phone and T-mobile decided to filter it as spam and not tell me.  Something fishy - I need to buy a very expensive short code to chat with other people.   I  am a long term t-mobile customers ready to cancel.  

12 replies

Userlevel 5

Hey there!

Just to clarify, is the customer you're trying to receive a message from using a short code? Do you happen to know the type of rate plan you are on?

With that info, we'll move forward and continue to try and help!


no they are using a long code. this is my app on my website - for visitors

who want to ask a question from an expert (Me).

It is low volume number of messages so It could look like spam due to

similar text as my webform formats the text with labels etc. I figured by

now Tmobile would convert over to local long codes (RCS) but that did not

happen.  I cannot justify a shortcode, it would be cheaper for me to build

a messaging app and will likely do so in the mid-term as the SMS is not

really secure and it is being harvested on.

I see due to recent sms hacking why



Userlevel 6
Badge +14

So, the messages are being converted to a long numeric code that's not a phone number? RCS messaging is automatically enabled on devices that support it. Making sure that the devices have a necessary connection is the something you'll wanna make sure of in order to make sure Advanced Messaging works.

thank for replay but I don't follow you.  link?

my phone is XXX-XXX-XXXX.   My customer is sending me a message from my website on  a long code. It is not delivered. You are suggesting my phone setting can fix this issue? I am on a  iphone xr and a samsung flip phone both fail. please advise

*edited by tmo_ian to remove personal information*

addanced messaging link is deal

the message is blocked by t-mobile as spam. The sms backbone we use said t-mobile rejected it because it was A2P. Which it is not. This is purely subjective as far as i can tell.

Do I need to switch mobile carrier to get this to work.  This is not a fair and open arbitration system form t-mobile. Just this forum.  Please advise.  So when do you deem my phone conversations Spam?  just wondering where does tmobile draw the line. This is unfair IMO.

Userlevel 6
Badge +14

If this is supposed to be a regular SMS, we'll just focus on that instead the Advanced Messaging service. Is there a way to check the status of the message from the sending end? T-Mobile can check the account of the receiver to make sure there isn't any blocking for messages, but the account holder would need to call in and have that looked at.

Userlevel 2
Badge +10

We're you able to try out Mike's suggestion and have the receiver contact us for additional Support?

Userlevel 3
Badge +3

This thread was brought to my attention. I'm the anti-spam engineer for messaging and would like to receive further details over D.M., so I sent you a follow request. I would like to obtain the number in D.M. and some supporting details to understand how we can resolve this.

Both inter-carrier and T-Mobile follow CTIA texting volume guidelines when it comes to P2P (person to person) and A2P (Application to Person) traffic. If automation messages are routing over P2P channels, the number may flag in T-Mobile anti-spam for volumetric and content reasons and also independently by inter-carrier anti-spam detection. The reason being, A2P content must be sent over designated shortcode aggregator traffic to comply with TCPA CAN SPAM ACT. The recipient must opt-in PRIOR to receiving the first text message. There are federal restrictions on receiving texts per time-of-day, region, and the possibility of prepaid plans receiving billable charges. A recipient must be briefed on these issues before the 1st text is received on the device.

Please see CTIA section 3.3, 4.2, and 4.3 to understand how message classification is defined.


You helped me last October/November with anti-spam...thank you very much. At that time, I asked if a .email TLD would be OK, and you confirmed it would be ok. We tried testing it today, and TMobile seems to not deliver the texts after the first one.

This is not business to consumer, it is for messaging our own employees when our equipment throws an alarm. Using a longer domain name we were using last October, the messages go through. The same messages are not going through when coming from our authenticated .email TLD.

I wrote you a private message a bit earlier.

Looking forward to another dose of you excellent support! 😉

I'm having the same issue and I'm just a regular T-Mobile user. I cannot sent text messages.  When I call T-Mobile I was told that a 10 day block was put on my phone because of either reported for Spam or sending Spam I have done neither. Nobody at T-Mobile can really explain to me why they put a 10 day block on my phone and now after 9 years with T-Mobile i may leavve! Can anyone help me. I was waiting on a call from a manager name "Earl" per a supervisor named Ramfis but never received it on 5 November 2020

When I send email to text with either links or pictures to MYSELF I get this message (of course I changed my number to x’s:

Your message to couldn't be delivered. suspects your message is spam and rejected it.