Why am I seeing RoadRunner deferrals and rejections for reputable senders?

Email marketer from Reddit shares that they've had success by ensuring their sending domain has a clean reputation and warming up their IP address gradually. They also suggest monitoring bounce rates closely.

Email marketer from Mailjet Blog shares that RoadRunner and other cable providers often have aggressive spam filters due to the residential nature of their user base. Senders should ensure proper authentication (SPF, DKIM, DMARC), maintain low complaint rates, and segment their lists effectively.

Marketer from Email Geeks mentions contacting Proofpoint will help you. TWC is using Proofpoint and Cloudmark for their filtering decisions and these particular rate limits are part of what Proofpoint does.

Email marketer from Email Marketing Forum suggests checking the domain's reputation using tools like Sender Score and ensuring the domain is not blacklisted. Also, properly configure SPF, DKIM, and DMARC records.

Email marketer from Email Marketing Forum advises segmenting email lists and cleaning them regularly to remove invalid or inactive email addresses. This helps improve sender reputation and avoid spam filters.

Email marketer from SendPulse Blog responds that deliverability issues with RoadRunner can stem from blacklisting, poor sender reputation, or content triggering spam filters. Monitoring sender reputation and using a dedicated IP address can help.

Marketer from Email Geeks shares the same experience and says that they've struggled with these cable-based email providers and a lack of a true postmaster to contact.

Email marketer from StackOverflow answers that ensuring your SPF record includes all IPs that send email from your domain, including third-party senders, is crucial for deliverability to RoadRunner. An incorrect SPF record can cause deferrals and rejections.

Marketer from Email Geeks shares that they always have issues with RoadRunner even for those with good habits.

Email marketer from Email Hippo Blog explains that RoadRunner (Spectrum) is known for having strict email filtering policies and can be challenging for even reputable senders. Common causes include hitting spam traps, poor list hygiene, or sudden increases in sending volume.

Email marketer from Reddit mentions that RoadRunner uses Proofpoint for email filtering, so it's important to adhere to Proofpoint's best practices for email sending. He suggests reviewing Proofpoint's documentation.

Expert from Email Geeks suggests there are significant problems with that sender’s data collection and management. There are a lot of dead addresses that haven’t been pruned when the rr.com domains were deprecated years ago and there are a lot of other signals telling cloudmark that these emails are likely not opt-in.

Expert from Spamresource.com explains that RoadRunner, like many ISPs, places a strong emphasis on email authentication. Senders experiencing issues should ensure they have properly configured SPF, DKIM, and DMARC records. They also advise checking for any misconfigurations or errors in these records.

Expert from Wordtothewise.com explains that participating in feedback loops (FBLs) with ISPs like RoadRunner is essential for identifying and addressing spam complaints. FBLs provide senders with data on which subscribers are marking their emails as spam, allowing them to remove those subscribers from their lists.

Expert from Spamresource.com responds that maintaining a clean and engaged email list is crucial for avoiding deliverability issues with RoadRunner. This includes regularly removing inactive subscribers and suppressing known complainers. Poor list hygiene can lead to higher bounce rates and spam complaints, negatively impacting sender reputation.

Expert from Wordtothewise.com answers that RoadRunner's filtering is heavily influenced by sender reputation. Senders should monitor their IP and domain reputation using tools like Sender Score and Reputation Authority. Negative reputation can lead to deliverability problems, even for senders with good practices otherwise.

Expert from Email Geeks explains that '[internal]' is a “fake” bounce created by the MTA. 'no mail servers for this domain could be reached' means there are no MXs for that domain or the MXs are pointing to domains / IPs that are not reachable.

Expert from Email Geeks explains the other rejection is a very specific block against that sender.

Documentation from Microsoft Docs explains that deferrals can occur when a receiving server is temporarily unable to accept mail. This can be due to network issues, server overload, or greylisting techniques employed by the recipient.

Documentation from Spamhaus explains that senders can use their blocklist lookup tool to check if their sending IP or domain is listed. Being on a blocklist can cause deliverability issues with various ISPs, including RoadRunner.

Documentation from DMARC.org explains that implementing a DMARC policy can help control how email receivers handle unauthenticated emails from your domain. This can improve deliverability and prevent spoofing.

Documentation from RFC 5321 explains that 4xx SMTP codes indicate temporary failures and deferrals. The specific code '421' indicates that the service is unavailable, possibly due to a temporary overload or maintenance. This suggests a temporary issue on RoadRunner's side.

Documentation from Google's Gmail Help provides best practices for bulk email senders, which are generally applicable to all ISPs, including RoadRunner. This includes proper authentication, managing subscription lists, and monitoring feedback loops.