Summary
AT&T email clients experienced widespread blocking issues over a recent weekend, affecting multiple domains and dedicated IP addresses across various sending platforms. This disruption was attributed to a major outage on AT&T's side, leading to a surge in blocked email bounces.
Key findings
- Widespread impact: Many senders reported emails being blocked by AT&T (including domains like att.net, sbcglobal.net, and bellsouth.net) starting on a Friday or Saturday.
- Root cause: The blocking was primarily due to a significant internal outage within AT&T's email infrastructure, rather than sender-specific reputation issues.
- Resolution timeline: Most issues were resolved by Monday morning, indicating a relatively quick recovery from AT&T's side.
- Varying impact: Not all IPs or clients were affected uniformly, with some experiencing blocks on specific IPs while others remained unaffected.
- Contact points: During such events, contacting AT&T's postmaster team at abuse_rbl@abuse-att.net or reaching out to direct contacts within AT&T (Yahoo Inc.) can expedite issue resolution.
Key considerations
- Monitor delivery metrics: Continuously monitor your email deliverability to AT&T domains (and others) to quickly identify sudden spikes in bounces or blockages. Suped's increased email bounces at AT&T guide can provide further insight.
- Identify cause: Differentiate between general ISP outages and specific sender reputation issues. Error messages in bounces can often provide clues.
- Stay informed: Follow community forums and news outlets like BleepingComputer for technology news that report major ISP outages or service disruptions that could impact email delivery.
- Proactive outreach: In cases of widespread blocks due to ISP outages, patience is key, but proactive communication with their postmaster can help ensure your IPs are on their radar for delisting once the outage is resolved. Learn what to do if AT&T blocks your emails.
What email marketers say
Email marketers widely reported facing significant email blocking issues with AT&T domains over a specific weekend. The consensus indicated this was a systemic problem affecting various clients and sending platforms, rather than isolated incidents of poor sender reputation. Many noted the sudden onset and the broad impact across different IP ranges.
Key opinions
- Sudden onset: Marketers observed that the blocking began abruptly on a Friday or Saturday, affecting multiple clients concurrently.
- Broad impact: The issue wasn't limited to a single platform or IP, but impacted clients on totally different platforms and multiple dedicated IP addresses.
- Systemic problem: The widespread nature suggested an issue originating from AT&T's infrastructure, rather than individual sender compliance.
- Spam wave connection: Some community discussions linked the blocks to a high volume of spam originating from certain services, suggesting AT&T's filters were reacting broadly.
- Resolution noted: Marketers confirmed the issue was resolved by the following Monday morning, indicating the outage was temporary.
Key considerations
- Collaborate and share: Share observations and block details within the email marketing community to confirm if issues are widespread or isolated. This helps diagnose root causes.
- Contact postmasters: Proactively reach out to AT&T's postmaster team (e.g., abuse_rbl@abuse-att.net) with specific IP addresses and bounce messages. This is crucial for getting details from AT&T.
- Understand ISP infrastructure: Acknowledge that major ISPs like AT&T (which encompasses domains like sbcglobal.net and bellsouth.net) have complex infrastructures. Issues can stem from their side due to maintenance, outages, or high spam volumes. Understand how AT&T handles email filtering.
- Patience and persistence: While internal outages resolve themselves, providing data to the ISP can still aid in their diagnostic process and ensure your traffic is prioritized once the system stabilizes.
- Check public forums: Monitor community forums like Constant Contact Community for similar reports from other marketers, which can confirm a broader issue.
Marketer view
Email marketer from Email Geeks observed that multiple clients were being blocked at AT&T, and inquired if others were experiencing similar issues. This highlighted the sudden onset of a widespread problem impacting various senders.
Marketer view
Marketer from Email Geeks reported seeing blocking as well, noting that clients on totally different platforms began experiencing issues around the same time, indicating a broad, systemic problem.
What the experts say
Experts quickly identified the root cause of the widespread AT&T email blocking as a major internal outage. This insight was critical, as it shifted the focus from sender-side issues to an ISP-level problem, enabling senders to understand that the fix would come from AT&T directly. The prompt communication from an AT&T/Yahoo Inc. representative about the outage and its resolution was highly valued by the email deliverability community.
Key opinions
- Major outage: The primary cause of the email blocking was identified as a significant outage within AT&T's network, impacting email services over the weekend.
- Internal issue: This was an AT&T server-side problem, not an issue with sender reputation or configuration.
- Direct communication: An expert from Yahoo Inc. (which handles AT&T's email infrastructure) provided direct confirmation of the outage and offered assistance.
- Swift resolution: The expert confirmed that most of the issues were fixed quickly, by the following Monday.
- Offer of assistance: Experts offered to directly check IPs for affected senders, streamlining the troubleshooting process during the outage.
Key considerations
- Trust authoritative sources: During widespread outages, information from direct ISP contacts or established industry experts is invaluable for accurate diagnosis and timely updates.
- Understand ISP operations: Recognize that major ISPs can experience outages or system overloads (e.g., due to spam waves), which temporarily impact deliverability regardless of sender reputation. This often leads to a spike in block bounces at AT&T.
- Maintain strong fundamentals: Even if an outage is the cause, maintaining proper email authentication (SPF, DKIM, DMARC) ensures your legitimacy once service is restored. For details on how these work, read our simple guide to DMARC, SPF, and DKIM.
- Utilize available contacts: Know the correct postmaster email addresses (e.g., abuse_rbl@abuse-att.net) for major ISPs for direct outreach during critical periods.
- Verify resolution: After an announced fix, continue to monitor delivery rates to ensure the problem is fully resolved for your specific sending infrastructure.
Expert view
Expert Lili Crowley from Email Geeks clarified that AT&T had experienced a major outage over the weekend, which was the direct cause of the widespread email blocking. She offered to help members by checking their specific IPs. This was a crucial piece of information that helped senders understand the nature of the problem.
Expert view
Expert Lili Crowley from Email Geeks further updated the community that most of the issues related to the AT&T email blocking should be fixed. This provided relief and confirmed that the problem was being actively addressed and resolved by the ISP.
What the documentation says
Official AT&T documentation and related technical reports indicate that service interruptions, spam waves, and incorrect client configurations are common reasons for email delivery issues. AT&T's policy often includes notifying domains of intent to block, emphasizing security gaps and potential abuse. During major incidents, their systems may react broadly to protect users from high-volume threats, sometimes leading to temporary collateral blockages that are resolved once the threat subsides or systems stabilize.
Key findings
- Common causes for issues: AT&T support articles list reasons for email problems including incorrect settings, server issues, full storage, and spam folder problems.
- Spam wave response: AT&T's email servers may block connections (e.g., from Microsoft 365) due to a high volume spam wave originating from a service, causing widespread delivery delays or blocks.
- Notification policy: AT&T's policy typically involves notifying domains of an intent to block them, along with the specific reason, before implementing the blocklist action.
- Security gap rejections: Their servers are likely configured to reject messages from domains or IPs that have certain security gaps or do not use secure connections like TLS.
Key considerations
- Review AT&T support: Consult official AT&T email customer support resources for common troubleshooting tips, as some issues might be resolved by adjusting settings or checking basic connectivity.
- Adhere to security standards: Ensure your email sending infrastructure (including client configurations) adheres to modern security standards, such as using TLS for SMTP connections.
- Understand ISP policies: Be aware of ISP policies regarding blocks and notifications. AT&T's policy to inform domains before blocking them can provide a window for proactive remediation.
- Monitor spam volume: If sending through a large email service provider, be mindful that a significant spam wave from that provider could trigger broad blocks from ISPs like AT&T. This is a common factor for block bounces to AT&T domains.
Technical article
AT&T Customer Support documentation advises users experiencing email problems to troubleshoot common issues like incorrect account settings, server issues, or full email storage. This implies that while outages occur, user-side issues are also frequent causes of non-delivery.
Technical article
AT&T Small Business documentation states that it is their policy to first notify any domain of their intent to block them, along with the specific reason. This highlights a commitment to transparency before implementing blocklist actions, allowing senders a chance to rectify issues.
Related resources
7 resources
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