VText Not receiving email from my company's SMTP server.

[bgrantme]

I also need help with this. I noticed a standard 12:00pm text alert did not arrive on my phone today 7/6/21 and looking at the postfix log for the server that would have pushed it out, I have the same type of warnings (multiple cloudfilter.net addresses are listed in the log, not just this one): 

host vrz-sms.mx.a.cloudfilter.net[35.165.168.89] refused to talk to me: 554 CMGW cmsmtp <my external IP address> blocked AUP#DNS

The status of the message is currently "deferred" but I expect it will fail after the required amount of time elapses.

Our external IP address is in our SPF record for our domain.

I don't know when the problem began, because I came into the on-call rotation today, so today was the first time I'd expect any message to come to <myphonenumber>@vtext.com from our Nagios server. The on-call people  last week were not sending alerts to the @VTEXT.com domain (they use ATT) so no way to know. 

I can send a message successfully from our Gmail to <myphonenumber>@vtext.com. 

[vzw_customer_support]

It's imperative that your email concerns are resolved. Our Business support team can be reached by phone at 800-922-0204 and are not available via this platform. In order to work with Business support, please contact them at the number above during hours of operation Mon-Fri8:00AM - 8:00 PM Local Time. We apologize for any inconvenience. 

[vzw_customer_support]

Making sure that you can work with our Business technical support team is key. As mentioned in the previous response. Our Business support team can be reached by phone at 800-922-0204 and are not available via this platform. In order to work with Business support, please contact them at the number above during hours of operation Mon-Fri8:00AM - 8:00 PM Local Time.

RitaH_VZW

[bgrantme]

Check https://check.spamhaus.org/ for any entries for your external IP address. I found that there was an entry for our external IP, which may well be the problem. I thankfully had the ability to change the external IP our internal postfix server NATs to to something else, and voila! the messages go through just fine. I know not everyone has that flexibility to select another IP, so attempting to mitigate issues if found on spamhaus (or perhaps another block list) may help.

I got no actual help from my long Verizon Support chat session and I kept asking if there is a block list they use that they could check (or a whitelist I could be added to...but fat chance) my IP for, since that is clearly what the error is calling out, but they never acknowledged that particular part of my questions, just ignored it. I don't remember now how in my research I stumbled upon spamhaus.org in particular as being one they use, but it seems to be a key player.

[adamjgp]

Thanks for the info.  I checked spamhaus.org and my IP is not listed there.

I've been in touch with Verizon support through their business account.  I've got a ticket open and am waiting to see what their network engineers find out.  I'll update when I Have more info

[vzw_customer_support]

Good morning, bgrantme! Being able to send and receive text messages is vital, and our goal is to help you in the best way possible. Can you please tell us a little more? Does this occur in a particular location or multiple locations? What is the make and model of your device? 

[bgrantme]

Hi Customer Support,

It's not a problem with my device, it's a problem with Verizon servers rejecting messages being sent from point A (a server I have) to any @VTEXT.com address. The rejection is clearly shown in my server's logs (it runs postfix and sends email, some of which is occasionally bound for a @VTEXT.com address, and started happening some time between June 21, 2021 and July 6, 2021.
The rejection of the mail coming from my server (whose IP address and configuration has not changed in years) is shown in this message and seems to reference an acceptable use policy (AUP) violation, but it's not clear what the violation is. I would like to have my IP address removed from whatever block list it's on that causes this rejection (understanding that you would need to see evidence of mitigation of issues.)

I know it's the IP address on a block list causing the problem because I had the ability to change the IP address to something different and the messages go out to @VTEXT.com addresses again with no problem. Most people probably can't change their external IP address and this isn't a real solution, just a diagnostic/workaround.

I can't post the actual IP addresses in this post but here is an example of what's logged in the mail server's mail.log for a failed send, and then for a successful one (which only occurred after changing the IP address). The values I obscured are in ALL CAPS:

fail:
Jul 6 15:38:11 MAILHOSTNAME postfix/smtp[31399]: 53721A2846: to=<[email address removed per the Verizon Terms of Service]>, relay=smtpin01.vzw.a.cloudfilter.net[34.200.143.151]:25, delay=13089, delays=13088/0.01/1/0, dsn=4.0.0, status=deferred (host smtpin01.vzw.a.cloudfilter.net[34.200.143.151] refused to talk to me: 554 vrz-ibgw-5003a.ext.cloudfilter.net cmsmtp MYEXTERNALIPADDRESS blocked AUP#DNS)

success:

Jul 6 17:58:13 MAILHOSTNAME postfix/smtp[5428]: 53721A2846: to=<[email address removed per the Verizon Terms of Service]>, relay=vrz-sms.mx.a.cloudfilter.net[35.167.120.54]:25, delay=21491, delays=21489/0.01/0.66/0.97, dsn=2.0.0, status=sent (250 2.0.0 0t51mcHj6q5Lp0t52mO6ZR mail accepted for delivery)

[vzw_customer_support]

Thank you for providing such detailed information. Verizon takes protecting our customer's personal and account information very seriously. Since we will need account-specific details from you, we’ve sent you  a Private Message on this topic:

http://spr.ly/6602yXvJE

RobertC_VZW

[adamjgp]

@vzw_customer_support 
I do not see a private message, and when I click the URL you linked it sends me back to the community search page.

[jav6]

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@adamjgp wrote:

@vzw_customer_support 
I do not see a private message, and when I click the URL you linked it sends me back to the community search page.

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