Question not working

  • 3 July 2023
  • 6 replies


I’ve been sending to a plain/text email to my SMS via everyday for years, and it has stopped working the last couple of weeks. My email server replies with this: 

The following address failed:        multiple delivery attempts failed


A few messages have gone through, but most of them fail. I’ve tried sending from different email accounts and they all fail. Seems like Tmobile’s server is down. Are there any workarounds?

6 replies

I have a ticket open for this.  I am receiving the messages when sent from Gmail, but not Yahoo, or my company’s mail server.

I'm in the same boat. I can receive from Gmail, but not from any other email or from my work's server.


Any updates?


Same here, i am sending with my own email server and all was working more or less until 9/4/23.  

My problem got resolved exactly 30 days after it started  No matter how many times i called or escalated, would anything happen.  I almost jumped ship. 

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I’m using iCloud mail now; however, this has happened in the past with gmail and other providers. The majority of my current failure messages say “host[]
   said: 452 4.1.0 <> server temporarily unavailable
   AUP#MXRT (in reply to MAIL FROM command)”.

Occasionally they say “host[]
   refused to talk to me: 421 cmsmtp too
   many sessions from AUP#CNCT” (the ‘17...’ IP of which represents iCloud).

Another rare one is: “host[]
   refused to talk to me: 421 cmsmtp blocked AUP#CNCT”

I know that “AUP” means “Acceptable Use Policy”, which suggests the failures are related to SPAM-checks. However, these are single messages, sent across a week (one week per month), to a single phone number - they’re not mass emails, forwarded, or sent to multiple phones.

I did find something that suggested that T-Mobile was going to give up on this service as it used antiquated technology, and/or that they had started charging for it if were business- or marketing-related. My messages are for work on-call purposes; however, work sends the email, and I’m choosing to send the text so my phone alerts me of the message.

I have been battling this for over a year.  Sending from various email accounts no longer work while others work.,,.,,,  This is going to my phone number. I can send from my phone just fine.  It is maddening.  What I see in my email “Your message couldn't be delivered. Despite repeated attempts to contact the recipient's email system it didn't respond.” I also have texts from American Messaging and so far those still work (what my company uses for alert pages).  I gave up working with TMO support.  Supposedly it was escalated to some higher tier support but I never was contacted and Each time I contact them I have to start the whole troubleshooting process\discussion over. No matter if I told them this is the 100th time I have called.