Email to text gateway is rejecting messages with 550 blocked error

  • 18 September 2019
  • 23 replies


For the past 3 weeks, messages sent to are being rejected and returned with a message like this:

550 permanent failure for one or more recipients (

I work for a large university and we use Google as our e-mail service, yet messages are blocked.  I also can't send mail from a subdomain within our main university domain that does not use GMail.  We have a proper SPF record and the sending mail server is allowed to send per the SPF record.

I have contacted t-mobile support by phone multiple times but the staff answering the phone are not able to address or even understand the problem.  Reading other similar posts here, I see that somehow you have to call in and get added to a 'approved sender' list.  Can somebody tell me what number to call for support that would understand this issue?



Best answer by tmo_chris 21 September 2019, 00:20

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23 replies

Userlevel 4

This definitely sounds like your domain is getting blocked by our spam filters. We will need to speak with you over the phone for this but you can mention to the specialist you speak with to look at internal document DOC-414999 for all the info they will need to get a ticket submitted to have your domain unblocked.

Halo Chris, I have exactly the same problem. Texting through gmail to cell numbers. All text to T-mobile phones got blocked.

I've called 611 from my cell and been on the phone for almost 1 hour but they cannot find the problem. I told them your answer and they said that T-mobile do not blocked domain unless International. And seems like nothing get blocked.

Same with the original post, this happened about 3 weeks ago. Never happened before, either when we use wifi nor when we use T-mobile hotspot from our cell. Now, nothing works.

Please help. We need some solution asap please. Thank you.

I also am having this issue, it just started on November 1st. We have been using a gmail account to send text messages to our phones for almost 3 years now and all of a sudden it is being blocked. I have 5 other employees with different carriers that do not have the issue and it is only mine with T-mobile. I also have spoken to three different technical support operators and no one can solve the issue. If someone could please respond I would greatly appreciate it.

Thank You

After searching for answers for this topic, our problem solved. For us, it is blocked because we changed the content of our message to something that immediately flagged as spam. Includes words like: click this, follow us, follow this link, view this at. And link to sosial media (instagram, facebook, etc.) will certainly make you flagged.

If this is relevant to you, try change the text back to what it used to be and try to sms it to your cell to see if it solve the problem.

Good luck.

Our messages do not have any of the content you suggested. They come from

the email and state the flooding as an example:

1 of 2

MSG:Alert Id: 471626

Alrt: Flash On Any, St: New, Dev: SIGNAL 197 - Dixie Hwy @ Aviation Wy, Tm:


(Con't) 2 of 2

12:51:35 PM, Crit: Critical, Evt: Flash Dixie Hwy Aviation Wy N/A

again, I have been getting these for 3 years without issue

I'd recommend heading over here: E-mail to SMS being blocked due to suspected SPAM

I found my answer there on I believe page There is a Srickar person that been wonderfully helping others with same problems. Good luck.

So the discussion on there is locked and I am not able to respond to

anything on there. The Srickar person I sent a follow request and am

waiting for them to respond, so I guess I am supposed to wait for the

approval to go through?

I find this ridiculous I have to jump through all of these hoops for an

issue T-Mobile should be handling since it is on your end.

Oh, I'm just a customer trying to help other customer.

Thank you! I wasn’t aware you were a customer, my apologies!

No worries 😊


I'm having the same problem where email-to-text from one of my domains hosted through and messages sent through, and using a couple of email accounts through GSuite are being blocked where the consistent message from the tmo server states: 

550 permanent failure for one or more recipients (

What baffles me is that sending the same message through one of my gmail addresses goes through without problems.

Could it be that my above stated domain (with a valid SPF record) is blacklisted by the tmomail server?

If so, how could my domain be removed from the blacklist?

If this is not the case, what causes the "550 permanent failure" when sending mail-to-text to our T-Mobile numbers?

Hope to receive a reply soon from a T-Mobile tech support staff.

Thank you.


We are having the same issue when trying to send a text to employees. We send employees text details about the jobs they are performing.

The reply from T-mobile is:

The response from the remote server was:

550 permanent failure for one or more recipients ( rejecting banned content)

Message blocked

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

I understand that the issue can be solved by being whitelisted. How can we accomplish that?

I should add that we have valid SPF and DKIM settings.

We have the same issue. 

I am having same issue . How can this issue be fixed.?

I am also having the same issue.  This just started happening.   I intentionally have our alerts going to my phone and those are now being blocked.    Probably too many going thru looking like spam.   Need to coordinate with the engineers to allow the msgs to go thru. 

I am getting the same type of errors.  Status: 5.1.1 (permanent failure) & 550 permanent failure for one or more recipients (  Have spoke with Tech support 2x and still getting blocked. 

I was also facing the same error. Now, I came to know about this. This allows to send the message overall in India only. So if we will add the india’s code(+91), then it can be resolved. Then this error will resolve.

try this:


Use the country code before the phone number.

How to reopen <my_number> after blocking.

I have tried to send sms from my computer by email but I got some errors and the above account was blocked. I would like to know what to do to reopen the account again. Thank you.

Has anyone figured out how to solve this error? If so please share 

This really is ridiculous.  Is blocking spam really a higher priority than a vital notification function??

I’m in a key executive position at my company and for years I’ve been alerted instantly to customer problems by auto-forwarding certain emails to my phone number at (for Verizon or Xfinity) or, years ago, AT&T.   Suddenly with T-Mobile I stopped getting these, leading to an important downgrade in my company’s responsiveness to customer alarms.  And it’s up to ME to get T-Mobile to whitelist any such address??  

This is the first thing I’ve seen from T-Mobile that says they are not at all in the same league as the big boys (Verizon and AT&T). 

C’mon, y’all!  Fix it!  Quit saying it’s my problem, not yours!  I can go back to the other guys real easy - and right now I’m wondering what other time bombs are lurking, as T-Mobile cuts corners on me. Grow up, get real. Please.


Please add me to the list of admins with this problem… our email to SMS has been working fine up until the last month with the same error:

Failed to deliver to ''
SMTP module(domain reports:
message text rejected by
550 permanent failure for one or more recipients (,,,


Multiple calls to support have not been fruitful even after pointing them to posts on this forum.


Please give guidance on how to fix this high priority problem.

I have the same problem.  I spoke to a T-Mobile rep who said they would submit a ticket to high-level support.  The response to the first ticket (after a 3-day wait) was that there was no error and that text messages were being received.    I again told the rep that the text messages were in fact NOT being sent through or received.  Another ticket was submitted.  After another three-day wait, the response from the “High Level” technical support was that GoDaddy had to update their system.  I asked specifically what needed to be updated and the rep said they did not have that information.  

Ok, so then I called GoDaddy and who said they did not know what needed to be changed or modified to get past a third party (T-Mobile) blocking the emails and that their system is up to date.  

I just switched my emails to another email host (DreamHost) and tried to send an email to a text and received the same error “550 permanent failure for one or more recipients (*********


Emails sent from Gmail and get sent through without a problem,

I have come to the conclusion that T-Mobile is blocking my company domain for some reason.  Multiple calls to T-Mobile and support tickets have not solved this issue.  T-Mobile needs to fix this.

This started happening today. I had communicated email to text for several years with Gmail account. I recieved the fowwlowing message:  

Address not found

Your message wasn't delivered to because the address couldn't be found, or is unable to receive mail.

I also received the following message lower in the email: 

The response from the remote server was:

550 permanent failure for one or more recipients ( Sender email address rejected)