421 4.2.0 sender rejected AUP#SNDR

Having the same problem..

I am forwarding a few messages from my gmail email account to my T-Mobile number so I can get text messages of those emails..

The last few days the T-Mobile service has been returning this error..

At first it was just having trouble and rejecting delivery.. Now its outright blocking the messages..

What is going on? I’m just a regular T-Mobile user with a personal phone number.. I don’t have a business account or anything.. I just want to forward some messages from my gmail to my phone as text messages.. What do I need to do to make that happen again?

It was working just fine last week, and for the last several months since I set it up.. But the past week its been failing, and now I’m getting this error.

Can someone help me with this please?

¡Gracias de antemano!

Same issue here.. any status on resolution? 

I have critical home automation come through as text messages such as water leaks, fires, glass breaking etc. They are not coming through for about the past week. 

Please advise T-Mobile how to fix this?

Same here. I haven't been getting my home automation notifications since Tuesday afternoon and all they do via support is give me the run around. I was supposed to get a tier 2 callback this morning at 9am, but they never called.

Maybe it's time to switch to Verizon.. their offer for $30 a line for 4 lines for new users is tempting plus a credit to bringing your own phone. Hmmmm

I'm seriously thinking about it. I've spent numerous hours with support on this. And even if they do fix the problem, I've noted that since sometime maybe around late March, my messages would be randomly delayed, sometimes over 24 hours.

It's sad, because my first cell phone was with T-Mobile, and I remember back then the support was excellent - a gold standard by which I've judged subsequent support experiences… I ended up moving to Sprint a long time ago for their "Unlimited Everything" plan.  I'd noted that the support with Sprint wasn't that great, but now that it's back to T-Mobile, it's *loads* worse.

Honestly, the path of least resistance is to switch my notifications to discord, but that just seems wrong. I *pay* for messaging and I'm supposed to get "support" if it's not working, so I feel like changing providers simply out of disgust for what they're putting me through. I get that the merging of networks is rough, so I'm trying to be tolerant, but if they're not going to the effort to make the transition smooth for their customers, then it does not speak well for them.

I learned via an SMS service called RingCentral that the spam filtering that was blocking my legitimate messages is due to new FCC rules about mobile carriers and spam filtering.

So I just submitted an FCC complaint at: https://consumercomplaints.fcc.gov/hc/en-us/requests/new?ticket_form_id=39744

that addresses what I believe to be an unintended side-effect: blocking of legitimate messages with little recourse for consumers. I suggest others facing these same issues should also submit their own complaints. Otherwise, we're subject to arbitrary blocking of our own sent messages and messages we want to receive.

Here’s the content:

I have a series of home automations that use my mobile carrier's email-to-text feature to notify me when something notable happens in my home. These messages can include a security camera alert, motion alerts, moisture alarms, smoke detector alerts, etc., among other mundane messages. The average number of messages I receive per day using that feature is roughly 10 messages and I do not use it to send messages to anyone else. I set up an email account on gmail to be used exclusively for this purpose. I have used this method of messaging for years without issue until April/May of 2022.

On Tuesday July 19th, my home automation messages completely stopped. It took me many calls to tech support at both Sprint (my original carrier) and T-Mobile before the block on my email account was lifted. It took 2 weeks to resolve and they told me there are no guarantees it wouldn't get blocked again.

In talking with the last tech support guy who was able to identify and (temporarily) resolve the problem, I learned a few things:

1. T-Mobile contracts with a third party (a company called CloudMark) to perform spam filtering.
2. There is no way for a customer to directly request to CloudMark that a block on an email address to be lifted.
3. Tech support personnel are largely unaware of the spam filtering in use (which is why it took so many separate interactions and 2 weeks to resolve my issue).
4. Recipients have no way of knowing if a legitimate message sent to them has been spam filtered. (There's no way to for example, check a spam folder.)
5. The random message delivery delays (which can be in excess of 24 hours) are due to the spam filtering mechanism. This causes messages to arrive in a non-chronological order and can delay messages where timeliness is critical (e.g. my basement is flooding).

I have thoroughly researched this issue over the past 2 weeks and when considering whether or not to change carriers, I discovered that this is an issue with other carriers as well (e.g., Verizon) and is a fairly recent issue. I have interacted with a number of other people in forums who experienced the same problems as me.

I think users should have the right to whitelist messages sent to themselves or the senders as "not spam", because this spam filtering is blocking legitimate messages. Users should have the right to request compensation for failure to deliver messages. Users should also have the right to opt out of spam filtering for messages sent to them. There needs to be transparency all-around. Spam should be handled the same way as email providers do: create a spam box and give users controls to fine-tune their spam filtering.

At the very least, if the usage of email-to-text features are allowed to be limited by carriers or messages filtered without customers' knowledge or consent, users should be informed as to those limitations, such as number of recipients and/or messages allowed within a time window, the delays they can expect to experience in delivery, and what indicators are used to block either their own outgoing messages or messages sent to them. I tried to look up and requested those guidelines from T-Mobile and they had no information to offer that would enable me to avoid getting my email account blocked.

Furthermore, there should be honesty. The tech support person I spoke with claimed that Cloudmark said that other users identified my email account as a source of spam, despite the fact that I have NEVER sent a message from that account to anyone other than myself and there is zero evidence my account was hacked or that I have any other recipients in my sent mailbox other than myself.

And under the additional info, I entered:

This isn't about receiving an unwanted text - it's about not receiving a wanted text, but the categories provided don't account for this circumstance - please update your form to address mobile carriers blocking legitimate messages under the guise of spam filtering.

https://www.t-mobile.com/support/plans-features/consumer-versus-non-consumer-text-messaging

might be some needed info in here..

I just checked out the Verizon plans. Much pricier than what I pay currently for whatever my plan is called now.  When I originally signed up, it was called "Unlimited Everything". But… the verizon plan does come with Hulu and Disney+.  We were thinking about subscribing to Hulu anyway...

hepcat72 wrote:

Hmmm… Yeah, the lack of a hotspot is somewhat of an issue. I rarely use it, but when I do, it's usually really important.

 Exactly.. same here. How can I work from the boat without it 🤷🏻

not a whole lot to block your signal out on the water as long as the antenna is pointed your way and youre close enough lol.

homes/businesses the signal gets to fight against mother nature plus every wire/piece of metal in your home