Solved

Email to SMS (tmomail.net) is blocking our domain for spam.



Show first post
This topic has been closed for comments

153 replies

Thanks for the prompt response @srickar

We are having a similar issue with mail being blocked. Error 550 xxx-xxx-xxxx@tmomail.net:blocked.

Can you please help?

@srickar​ can you follow me so I can send you info on the issue? Thanks.

Userlevel 3
Badge +4

Request was already granted. Sometimes it will say message cant be sent but it goes through anyway. I initiated a message to you. Thanks!

Hello, starting today we started having issues sending to Tmobile again after completely changing our server setup per your recommendation @srickar for Tmobile last month. here are the errors we are receiving:

"This is the mail system at host lite.serviceslogin.com. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <xxxxxxxxxx@tmomail.net>: host d79033b.ess.barracudanetworks.com[209.222.82.129] said: 550 permanent failure for one or more recipients (xxxxxxxxxx@tmomail.net:blocked) (in reply to end of DATA command)

Your assistance is appreciated,

Thanks, Dan.

Userlevel 3
Badge +4

Hi Dan,

It's because the messages look like phishing/finance spam.

Very short, plain text, with a URL and username that resembles an "account" sending out links. There is a distinct imbalance between the numeric to text ratio, and because it is a hit match to similar phishing activity, its being flagged. This SMTP interface is receiving similar phishing attacks using similar style.  Sorry, cannot whitelist external sources. Automation messages would work best sent through a trusted short code gateway, otherwise will require anti-spam scoring.

Abbreviated syntax like this is suspicious.

"acct-42943-xxxxxx-c6n6r"

Aggregation Partners   

Thanks for the feedback @srickar

Can you please follow me? I have already followed you.

I sent you a follow request, I would love to be able to DM you, as my Fire department is Considering asking all T-Mobile customers to just change carriers, as many members are not getting emergency messages (sent through the SMS gateway).

Userlevel 3
Badge +4

I thought I had worked with you previously?  I see that my follow request is pending your approval.

Hi srickar, I'm trying to follow you but still waiting for approval. Can you please approve it? thx

Good afternoon

I encounter this post Today and I have read all the posts since I am experiencing the same problem.

My company is canissoft corp (www.canissoft.com) which develops staffing solutions for Law Enforcement and First Responders and our software sends alerts to various users with various phone carriers At&T, Verison, etc. Now for the same time, T-Mobile is blocking the alerts.

Our technicians were able to figure out that is all in the Subject and not on the body of the alert message.

So, if you want to see your alert go through on the tmomail.net Network type the following "Database Mail Test" and you will see the alert properly delivered.

Now, of course, that you don't always want to send "Database Mail Test" as your subject, instead play with different methods until you don't get any more rejections/

My question is now for @srickar

How can we include our domain so that this does not occur again?

Thank you so much

Best regards,

Good afternoon

I encounter this post Today and I have read all the posts since I am experiencing the same problem.

My company is canissoft corp (www.canissoft.com) which develops staffing solutions for Law Enforcement and First Responders and our software sends alerts to various users with various phone carriers At&T, Verison, etc. Now for the same time, T-Mobile is blocking the alerts.

Our technicians were able to figure out that is all in the Subject and not on the body of the alert message.

So, if you want to see your alert go through on the tmomail.net Network type the following "Database Mail Test" and you will see the alert properly delivered.

Now, of course, that you don't always want to send "Database Mail Test" as your subject, instead play with different methods until you don't get any more rejections/

My question is now for @srickar

How can we include our domain so that this does not occur again?

Thank you so much

Best regards,

Userlevel 3
Badge +4

Anti-spam systems evaluate messages on various fields in header, subject, and content in message body. Messages were blocking for a combination of reasons. And with recent phish outbreaks, sending similar content which matches COVID-19 scams taking place during this same time period can result in false positive blocks.

In these examples, I am seeing:

  • Sending codes and simultaneously discussing password resets (phishing sources send in similar format).
  • Using short plain text with content containing a URL (avast[dot]com (phishing sources sending similar). I understand that avast is anti-virus scanning, but including this URL in every message footer, is counter productive as it makes the message a match hit to similar phishing messages who also insert URLs in the message body while discussing password reset.
  • Sending from a shared IP host (perfora.net), with a known spammy reputation. Perfora collocates some of the largest sources of phishing content.
  • An imbalance in text to numeric/punctuation ratio, meaning excessive use of digits in comparison to the amount of text.

Email requires anti-spam evaluation and attacks one one domain can vary differently from another recipient domain. Continued repetition of automation content triggers higher score filtering. For automation alerts, I would recommend converting to a trusted short code gateway. Trusted short codes are premium and offer delivery receipt. Spammers are not part of those gateways because it removes anonymity.

Email anti-spam evaluation best practices should always be present on sender and receiver side, which cannot guarantee delivery channel especially for automation traffic.  Please let me know if you have any questions.

How do I DM you?

Let me create a temp email and I will send it to you

Sent from Outlook Mobile

Userlevel 3
Badge +4

I responded to you on Monday April 20th but whatever was pasted wont work in DM.

Userlevel 3
Badge +4

@delphimpd,

Send me a follow request and I can DM with you.

Good afternoon Sir.

Mr. Antunez is not available. I am answering his messages.

May I know what "DM" is so I can pass the reference to Mr. Antunez.

Thank you

Roxana

Sent from Outlook Mobile

Userlevel 3
Badge +4

Direct Message, from inbox. But in order to be able to send private message, need to accept the request from the dashboard.

Good afternoon

Thanks for your reply,

can you reflect the steps on how to accept the request from the dashboard please.

Thank you

Roxana

I am facing a similar issue. I just requested to follow you so I can DM. Thank you!

Thanks for the reply.

And how do I accept message from the dashboard.

Thanks

Carlos

Sent from Outlook Mobile

I was actually writing to srickar as a customer. Sorry for the confusion - the message was not intended for you.

Not sure if this thread is dead…  I’m having an issue where I’m using a forwarder from my business email to my tmomail.net and nothing comes through.  I use these for server alerts after hours.   I can email my tmomail.net directly and works fine.  Only when I’m setting up a forwarder is where the text never appears.

 

thanks

 

 

Hi,
 
I am having emails blocked as well. These used to work, but have stopped. I send email messages from work systems for alerts of various error conditions.
 
I sent a test message last night and received this message that a Barracuda spam filter is blocking the message. At least that is my guess.
 
<xxxxxxxxxx@tmomail.net>: host
    d79033a.ess.barracudanetworks.com[209.222.82.126] said: 550 permanent
    failure for one or more recipients (xxxxxxxxxx@tmomail.net:blocked) (in
    reply to end of DATA command)
 
I did call T-mobile support and had the tech open an engineering support ticket. The gentleman I talked to did not seem to be very familiar with spam blocking issues though he was very helpful.
 
Any further assistance on this would be very much appreciated.
 
Thank you.
 
Patrick