Email Sender Blocked: AUP#In-1300

nnhariharan

As I could not find any method to contact Spectrum eMail postmaster for fixing email delivery issue, I am posting here for resolution.

Hi,

We have recently changed the IP address of our mail SMTP server and after that we started seeing the emails are being blocked by Spectrum mail servers with below errors.

550 5.1.0 <My IP> blocked. Please see https://www.spectrum.net/support/internet/understanding-email-error-codes for more information. AUP#In-

Some example domains we got bounce back (Masking email username & My IP for privacy):

Delivery failed 1 attempts: d*****c@woh.rr.com
Server response to MAIL FROM:
550 5.1.0 <my IP> blocked. Please see https://www.spectrum.net/support/internet/understanding-email-error-codes for more information. AUP#In-1300

Delivery failed 1 attempts: mi***_mo***r@twc.com
Server response to MAIL FROM:
550 5.1.0 <My IP> blocked. Please see https://www.spectrum.net/support/internet/understanding-email-error-codes for more information. AUP#In-1300

Delivery failed 1 attempts: go****@rochester.rr.com
Server response to MAIL FROM:
550 5.1.0 <My IP> blocked. Please see https://www.spectrum.net/support/internet/understanding-email-error-codes for more information. AUP#In-1300

We have over 3M customers worldwide. Customers must get emails for their registrations, temperature alerts which they have configured & subscribed in our devices.

We have proper reverse DNS record (PTR) has been configured for the new IP. We also have proper SPF and DKIM records. I have verified the IP address is not listed in any of the blocklist databases.

We want to allow / whitelist our IP ASAP to ensure our customers can receive the emails as they subscribed. We did not face any issue with the old IP.

I do not want to share my IP address, FROM address or my DNS record details in the public forum. It would be great if you can advise me on how to reach out the support to resolve this issue. I can share whatever details you ask in a private email / call.

Note: We had the same issue with Yahoo, Hotmail, Live, Comcast & other major email provider email IDs. After we had provided proper justification and all the details, they have mitigated the issue.

Regards,

Hariharan

James_M

Hi and welcome!

AUP #1300 is an Acceptable Use Policy error and references that the limit for concurrent connections has been exceeeded. I've included a link to Understanding Email Error Codes that explains this and other error codes.

Are you sending the emails from a personal, residential email or a business email? If it is a business email, does Spectrum manage the domain? Are you sending from your home account or using a static IP on business account?

nnhariharan

We have two SMTP servers in our corporate data center and we are sending email from a business email. Spectrum is not managing the domain.We own our Domain / IP space and also the servers. As this is corportae SMTP servers, the IP is 100% static.

As I had mentioned, We have proper reverse DNS record (PTR) has been configured for the new IP. We also have proper SPF and DKIM records. I have verified the IP address is not listed in any of the blocklist databases.

Our email servers send 500k emails every day to the customers, depends on their temperature / cooling alerts & notifications.

We need this to be fixed ASAP as customers using spectrum domains are not receiving their intended emails.

James_M

Thanks for the reply.

This Community supports users with a Spectrum email and issues impacting their individual residential email accounts. Simply put, it is possible that the emails in question are no longer active, have blocked your sending email or your domain has been marked as spam. It is also possible that the IP address being used has been flagged.

The full explanation of the AUP#1300 error is as follows:

AUP #1300 - 1340

Spectrum limits the number of concurrent connections from a sender, as well as the total number of connections allowed. Limits vary based on the reputation of the IP address. Reduce your number of connections and try again later.

nnhariharan

Ok, If this community is not a right place to discuss. Please let me know where I can report about this issue. Every day, my SMTP log reports atleast 3000 emails undelivered to spectrum email IDs.

Like I could reach Yahoo & Hotmail postmaster (either to fill form or postmaster email ID), How can I reach Spectrum email postmaster to discuss & report about this issue?

nnhariharan

My IP is not (& never) listed in any of the blacklist databases and over the period, the IP has gained good reputation and that is why major email providers have started accepting the emails,