Summary
Reverse DNS (rDNS) failures from AT&T often indicate a temporary issue on their end or an improper configuration of PTR records on the sender's side. When AT&T's mail servers receive an email, they perform a reverse DNS lookup to verify that the sending IP address matches the domain name provided. If this check fails, it can result in bouncebacks, impacting email deliverability to AT&T, SBC, and Bellsouth domains. While sometimes a systemic issue with AT&T's infrastructure, ensuring your own DNS records are correct is crucial for preventing these errors and maintaining good sender reputation.
Key findings
- Widespread occurrences: Many senders report simultaneous reverse DNS failures specifically from AT&T, suggesting a broader issue on AT&T's network rather than isolated problems.
- Network specific: The problem tends to affect specific AT&T IP ranges or data centers, indicating a localized network configuration or routing problem.
- Temporary nature: These failures are often temporary, resolving themselves as AT&T addresses the underlying network anomalies.
- PTR record enforcement: Receiving mail servers (like AT&T's) often enforce strict PTR record checks, making correct reverse DNS configuration essential for deliverability.
Key considerations
- Verify your rDNS: Even if AT&T is having issues, always confirm your own reverse DNS records are correctly configured and resolve to your sending domain. A misconfigured PTR record is a common cause of reverse DNS failures.
- Monitor AT&T status: Keep an eye on AT&T's official service status updates or community forums for announcements regarding network issues that might cause these failures.
- Impact on deliverability: Reverse DNS failures can lead to significant bounce rates, affecting your overall email deliverability to AT&T domains.
- Proactive infrastructure optimization: For long-term success, ensure your email infrastructure is optimized and robust against potential ISP-side issues.
What email marketers say
Email marketers frequently encounter reverse DNS failures from AT&T, often leading to immediate concerns about campaign performance and deliverability. Their experiences highlight how widespread these issues can be, impacting multiple senders simultaneously. While frustrating, many marketers recognize these as intermittent problems that may resolve on their own, though some have sought immediate workarounds to mitigate the impact on their email programs.
Key opinions
- Shared experience: Many marketers quickly confirm they are experiencing the same reverse DNS issues, indicating a collective impact rather than an isolated incident.
- Temporary nature: Initial reactions often involve hoping the issue is temporary and will resolve itself without direct intervention.
- Impact on campaigns: Reverse DNS failures translate directly to bounced emails, negatively affecting campaign reach and reported metrics, necessitating a quick resolution.
Key considerations
- Communication with ESPs: Marketers should communicate with their email service providers (ESPs) to understand how these failures are being handled and what steps are being taken.
- Audience impact: Consider the percentage of your audience using AT&T or associated domains (SBCGlobal, Bellsouth, etc.) to gauge the overall impact of such an outage.
- Alternative DNS settings: Some users have found success by adjusting their DNS settings or disabling specific AT&T features like "DNS Error Assist" on their network.
- Monitoring bounce rates: Actively monitor bounce rates specifically for AT&T recipient domains to identify when the issue begins and resolves. This proactive approach helps in troubleshooting and mitigating issues.
Marketer view
Marketer from Email Geeks observed widespread reverse DNS failures from AT&T this morning, noting a significant impact on their email operations. This indicated a potential network issue affecting multiple senders.
Marketer view
Marketer from The FreeBSD Forums detailed steps for checking if your DNS server correctly responds to reverse DNS queries. This is a crucial first step for diagnosing such failures.
What the experts say
Experts in email deliverability offer deeper insights into the technical nuances behind AT&T reverse DNS failures. They often confirm the widespread nature of such incidents and delve into potential root causes, from network routing issues to specific IP performance differences. Their guidance focuses on diagnostic steps and strategic workarounds, emphasizing that while waiting for an ISP-side fix is an option, proactive measures can sometimes mitigate the impact.
Key opinions
- Confirm widespread impact: Experts quickly validate that reverse DNS failures are affecting many users, confirming it's a systemic issue, not isolated to one sender.
- AT&T awareness: There's an understanding that AT&T is usually made aware of these widespread issues, though an estimated time of repair (ETA) might not be immediately available.
- Performance disparities: Certain IP addresses within AT&T's network may perform significantly better than others, leading to differential success rates in reverse DNS lookups.
- DNS hijacking concerns: AT&T's own documentation on DNS hijacking indicates their focus on DNS security, which might influence their handling of reverse DNS.
Key considerations
- Prioritize stable IPs: If possible, senders with administrative access should consider manually updating DNS caching or host records to prioritize AT&T's more reliable IP addresses during outages. This can significantly reduce reverse DNS bounce rates (see also why you're seeing reverse DNS failure bounces).
- Monitor DNS resolution: Continuously monitor DNS resolution specifically for AT&T's MX records to detect performance degradation or failures promptly.
- ISP communication: While awaiting a fix from AT&T, consider reaching out to their support channels for updates or to report ongoing issues. This can help escalate the problem.
- Full circle DNS checks: Ensure your sending infrastructure passes a full circle reverse DNS check to meet common deliverability standards, reducing the likelihood of being blocked by ISPs.
Expert view
Expert from Email Geeks confirmed the issue was widespread, affecting many users and not an isolated incident. They indicated that numerous reports were coming in from various channels.
Expert view
Expert from SpamResource.com states that a properly configured reverse DNS (PTR) record is a fundamental requirement for most receiving mail servers to accept email, and its absence or misconfiguration frequently leads to delivery failures.
What the documentation says
Technical documentation and official guidelines underscore the critical role of reverse DNS in email authentication and anti-spam measures. They clarify that PTR records are essential for an IP address to resolve back to a domain name, and failures in this process are often interpreted as suspicious activity. Documentation also hints at the complexity of large ISP networks, where localized DNS resolution issues can arise independently of sender configurations.
Key findings
- PTR record necessity: Properly configured PTR records (reverse DNS) are a prerequisite for many mail servers, including AT&T's, to accept incoming email.
- Bounceback cause: Bad or missing PTR records are a direct cause of bouncebacks when receiving servers enforce reverse DNS checks.
- ISP-side DNS issues: Even with correct sender configuration, large ISPs like AT&T can experience internal DNS resolution problems that impact email delivery.
- DNS error assist: AT&T has proprietary features like "DNS Error Assist" that can interfere with standard DNS behavior and lead to unexpected failures if not configured correctly.
Key considerations
- Standard compliance: Adhere to email authentication standards, including robust reverse DNS, to ensure broad compatibility with all ISPs.
- Delegation requirements: Understand that ISPs might have specific delegation requirements for reverse DNS, especially for subclass-c address spaces, which must be correctly configured.
- DNS resolver behavior: Be aware that issues can arise if an ISP's DNS resolver misinterprets or blocks outbound DNS traffic, sometimes requiring alternative DNS server configurations. This can be critical when troubleshooting timeout issues.
Technical article
Documentation from Spiceworks Community states that bad PTR records are a direct cause of reverse DNS bouncebacks, especially when the receiving end strictly enforces PTR record checks for email validation. Correcting these records is paramount for resolution.
Technical article
Documentation from The FreeBSD Forums outlines the initial diagnostic step for reverse DNS issues: checking if your DNS server correctly responds to `dig -x` commands for reverse lookups. This foundational check helps confirm local DNS health.
Related resources
10 resources
Related pages
Why am I seeing reverse DNS failure bounces from AT&T?
How do I perform a reverse DNS lookup and interpret the results?
How does a full circle reverse DNS check work?
Why are AT&T email domains experiencing a spike in block bounces?
What to do when AT&T blocks emails without providing details?
What could cause a sudden increase in DNS failure and hard bounces in email delivery?
What is a DNSBL and how does it affect email deliverability?
Why your emails fail: expert guide to improve email deliverability [2025]
A simple guide to DMARC, SPF, and DKIM
How to troubleshoot intermittent email delivery failures caused by SPF and DNS issues?
